At a guess, I'd say because they wanted to give you a bit more freedom- this way, you still can make a guy who knows martial arts, including some armed ones- but you can also have a character with the Armed Arts stunt representing the ability to brawl with whatever comes to hand, by using it to allow Fists to attack with bottles, chairs, tables, bits of pipe...

The problem with this is that the cell phone itself doesn't understand symbolic links.   Humans understand symbolic links, and the phone number is a far stronger symbolic link than the IMSI.  

See, I'd always interpret it as a link in the caster's mind, not in the target's. Sure, they need to get it right- but "the mobile phone identified by this serial number" seems as valid to me as "the person with the hair on his head that this piece of hair was part of."

So yes, you can use your specializations with sponsored magic just fine.

True, but that's not quite the issue. The question is whether you can have a Summer specialisation in Evocation; that only addresses using the other Summer magic benefits with a normal-element specialisation.

Hrm.

Physical: Cold iron, fire, wood, leather, that sort of thing for substance-catches; strangling, bludgeoning, cutting, or stabbing injuries; "things that have been alive"; a single weak point that's easy to hit, as long as you know it's there.

Mental: Mental stuff's often used for resisting torture, so maybe strobe lighting (or even just bright lights) are the sort of thing that come to mind; more esoteric things might include a prolonged loud or dissonant noise, or any simple technique anyone could set up- dripping water, sensory deprivation, hair-pulling...

Does that help?

It's more that I'm not totally sure the players will be OK with this plot point for a few reasons, not the least of which is none of the PCs are your typical "gamer sociopaths".

Won't that just make it more fun and interesting and fun...?

Fair enough- but if I was running, even for that sort of a fight, I'd prefer to make people have a high chance of doing a lot of damage, instead of a small chance of instantly killing (or worse) the target. (Obviously your game's not my game, and this is an opinion.)

Area attacks take 2 more shifts of power, so yeah, you need a result 2 higher on the Discipline roll, and are also more likely to take more Stress from the power- a Weapon 3 area attack is a 5-shift spell, and casts the same way as a Weapon 5 single-target one.