I think no one's really doubting that the instances of Soulfire we see in the books are granted from the white god, via Uriel, but the question is can any other sources grant it? Like say, Hephaestus or Marduk or someone. Craftsmanship gods and Creator gods in general.

But anyway, we should be careful not to stray to far away from the original question.

I am having a bit of trouble wrapping my head around some of the sponsored magic flavours. Soul-fire requiring goodynies I can live with, but Kemmlerian Necromancy really ticks me of. What source of power does it draw on, specifically? I can only think of death itself and I just don't see death as having so much of an agenda.
I feel that if an bad guy is using sponsored magic this should limit him somehow, allowing the players to get an edge in once they recognize the pattern, but what does kemmlerian force a necromancer to do what he would not have done already?
The same goes for the layline sponsor in the neutral grounds case file. I understand that some sources might be more mysterious and knowledgeable, but that seems to make them also unplayable or at least flavourless and bland when they come in to play.

Anyhow, I am sure this has been addressed in the past, I just haven't been able to find it yet.

I think Kemmlerian Necromancy is tapping into enthropy somehow. I don't have access to my books at the moment, but I think you should go look at that place in the books where Harry accidentally wakes up evil Bob. And really any place with evil Bob is probably going to tell you more about how Kemmler acted than I could, and he was presumably in deep with the source, given that it's named after him.

What you could do about other "mysterious" and knowledgeable sources is sit down and consider where the sponsor's goals differ from the sponsee (is that a word?) and go from there. Maybe together with the player? (assuming you are the GM) Give him stuff when they agree and deny him when they don't. Think Pavlovian dogs. Of course if your problem is that you don't know your sponsors goals, then you need to make them first. Think about what their needs are, and what if any beliefs are associated with them. Often sponsors don't have or even understand human needs, like sleep or food, but they may have something they need the same way, like prayer or sunlight or something. Look over the needs-hierarchy pyramid and substitute the human needs with the sponsors needs. Switch it around if it feels appropriate. Maybe for gods esteem needs are more important than physiological needs?

How about instead of restricting it to a specific list of trappings that are forbidden, you say something like:

"Incapable Of Thought. Not being able to think has its downsides. There are some skill trappings you may never use. Have the GM go through the skill list and cross out trappings that your specific type of mindless would not logically be able to use. The following list is suggested as forbidden for golems, but you may need to adjust for robots: [insert list here]
Superior Instincts/Programming [-1]. The complexity of your program or your instincts is impressive. Select up to three skill trappings. Ignore the effects of Incapable Of Thought on those trappings. This trapping may be purchased multiple times."

A bit better maybe? You may want some kind of set number for least amount of skill trappings to be forbidden and you might want to have some kind of cummulative price increase for each time you take Superiour Instincts/Programming

I also suggest reminding the GM that social consequences may come to the "owner" of the mindless thing instead of the thing itself. If the owner is known, that is.

Oh, right! I forgot that. Hm, not sure actually. I want to say physical, but it's magic, you know. That's usually something you sense mystically. And it doesn't actually correspond to a sense that humans normally have, but it basically translates as vision. Or heat vision, rather, where the more magical you are the more you glow. I'm gonna say physical, but this is one of those things a GM can easily change without much impact.

I made an item of power and thought I'd add it here for critique.

Eye of the Graeae from [-1] to [-4]
Description: A false eye made of amethyst that grants the user the power to use The Sight. With use, a wielder of the Eye can awaken other powers in it. It is not in fact the actual Eye of the Graeae, but a clever imitation made by a scion of Hephaestus who intended it as a gift to the Grey Sisters, but he was killed before he could give it to them and his killer picked it up. He in turn lost it in a bet with a Sidhe Lady and it has been in the Nevernever since. Even though it is not the original, it conveys various powers of sight on the owner and over time it has acquired some magical power due to its connection to the Grey Witches.
Musts: You must have an aspect related to your possession of this item.
Skills Affected: Lore, Discipline, Alertness, Investigation
Effects:
[-0] It Is What It Is. It's a false eye. Therefore, in order to make use of the Eye of the Graeae, a character must lose an eye and place the Eye of the Graeae in its stead. Like the original, you can use its power even when you hold it in your hand. However, to do this, it needs to be attuned to you by resting in your eye-socket. The eye does not grant standard vision - it is, after all, a false eye - and thus the Aspect associated with this Item will be compelled quite often for situations requiring depth perception or mundane vision, depending on whether your other eye works properly or not. 
[-0] Unbreakable. The Eye of the Graeae, as an Item of Power, cannot be broken except with a magical ritual predicated upon perverting its purpose.
[+1] One-Time Discount. The Eye of the Graeae is easily concealed. You could pop it out and hide it in you pocket, or you could just keep your eye closed.
[-1] The Sight. The purpose of the Eye was to help you see, and whatever you see with it is true and real. Needs to be activated, like the normal Sight power.
Upgrades:
[-0] Cassandra's Tears. Because the Eye sees that which is true, it can sometimes see what will be as well as what is.
[-1] Supernatural Sense. The Eye of the Graeae lets you see magic, as if it were colour or heat. This lets you see auras, tell wizards from mundanes or spirits at a distance by their glow, read the patterns of spell residue and anything else the GM thinks reasonable.
[-3] Thaumaturgy. The Eye of the Graeae gives you the power to cast spells like a witch.
Notes:
The One-Time Discount does not apply until there is at least a -2 cost of powers to link it to.
Thaumaturgy may be bought as Ritual first. If so, it is restricted to something traditionally witchy, like Craft Potion or Enthropomancy.
The Eye does not grant normal vision. You cannot read with it, tell what colour something is nor any number of little things that you need normal non-metaphoric vision to do.

edit: Don't know who the Graeae are? see here.
edit 2: Modified.

Honestly, a part of me thinks Social conflict is better without any weapon ratings. To me, the whole Social conflict thing seems like it's supposed to be "softer" than Mental or Physical conflict. Like, a social consequence that lasts months and years at a time really isn't supposed to be something that comes normally.

Part of this goes back to my feeling that social combat and the possibility of filling all your consequences with social stuff and making yourself a sitting duck in combat is way off. Part of it is that Social consequences seem much more transient in nature than physical or mental stuff, things that literally and tangibly change you and who you are.

Really? You don't think it would last as long?  How about, a bad breakup that ends in the ex badmouthing you to all your mutual friends for months, or someone being accused of paedophilia and losing their teaching job and their reputation and in some cases even their rights for years. Wouldn't those be social consequences? You may be the same old stand-up guy you've always been, but if everyone views you in a different light, that's going to affect you. Right? Unless you have no social antennas you're going to notice if no-one wants to go on a second date with you cause your ex has been dishing the dirt. Or worse, if the Moms in the neighbourhood are keeping the kids away from you and looking at you like a threat.

I don't really have a point of view on the rest of the discussion, but that just struck me as wrong.

Personally I wouldn't allow it, I'd put it in the same realm as targetting an opponent with evocation through a crystal ball/scrying device and, according to YS, evocation cannot be targetted through: . The ability to see through walls, would be, to me anyway, a similar effect to scrying an opponent.

Well, I would think that if this power was something innate to you, something you did as easily as breathing, then that wall would hamper you about as much as a glass wall. However, if you have to think about it to be able to do it, it would be the same as trying to use evocation through scrying. Because they explain the line-of-sight rule by saying that you can't concentrate on two spells at the same time.

if you have to concentrate on a second spell to find your target, it's just too much

Which reminds me, I was going to write up a multiple-personality spellcaster.

Nah. If anyone wanted us to stop, they'd tell us to, right?

Uhm, did you miss this?

If you're all bored of the argument and/or actually in agreement, do you think it would be possible to get back to discussing the original subject? *hopeful* Because I always get a bit disappointed when I see a subject with a title that really interests me not be about that subject at all...

Say for instance: When would you say the "technology and magic don't mix" thing started?
and what changes do you think would be necessary to the system to set the campaign in 1875 and what would you change (if any) to set the campaign in 1960s?

Though I have really given up at this point.

Yeah, that's a valid perspective on hexing. But I think of it somewhat differently. To me, hexing is the result of random drift in physics resulting from the vagaries of a mortal mind commanding magic.

Hm, maybe. Perhaps there is some overlap between the two, like Mr. Death suggested.

The difference shouldn't matter too too much, but if it bugs you feel free to make whatever changes you want to what I wrote. I doubt I'll be able to help you much with that, though, because my historical knowledge is pretty weak.

I think I'll make my own actually. I should really have done that in the first place, but I didn't really have the time to do the research it deserves at the momement. (I still don't, so don't expect it untill maybe June.) Thank you for the effort though.