Probably not unless it was inherited and made of silver.

Sounds like you and your group has a pretty good handle on the downside of having a band of pixies about, sounds like all you need is the aspect to deal with them. Just let your GM know you'd like compel on the Pixies then let your GM and fellow players play the pixies and make your life hell and sit back and reap in the fate points. I love the Reel to Reel movie night, the consequence of missing movie night sounds like it could be pretty dire compel. 

I know I had enough trouble/fun dealing with just one when I played a rich, reclusive, Wizard in a 1920's Chicago game with a single Pixie Gal Friday, dealing with 13 pixies should be a ball.

True there isn't anything on Harry's sheet about being the Za Lord. But then his Aspects can change at any of the milestones he went through and he probably eventually gets around to changing one of them to something like I am the Za Lord or he might not have depending on how relevant it was to the story that he and his group were telling. Basically any trouble from it could always be compelled off of his Perpetually Broke aspect that he keeps having to buy extra pizza for Faeries every week. Really until it gets brought up in the fiction of their game by Contacts or Resources rolls, being the Za Lord isn't really worth or cost any Refresh points.

But getting back to the OP's question I'd say that the character's aspect "A loyal staff bound by blood, love, and bargains" should do most of the heavy lifting when it comes to dealing with the Pixie Army, Fae Major Domo, and any old family friends. Invoke it whenever you need a bonus when dealing with them, and Compel it whenever those bonds of blood, love, and bargains become an issue.

All sorts of juicy Compels leap to mind with that sort of aspect. Just what did your great, great grand ancestor do to bind a Fae to his family for all this time, do you need to do it again? Sometimes Pizza Guys are late, what happens then? Crazy old Uncle Eustace shows up at your door claiming that someone is after him and he needs a place to hide, what if that someone is a Warden?

Now if you want the Pixie army to become even more effective information gatherers then a pick up a stunt called something like "Pixie Spymaster" which could give you a bonus to Contacting rolls possibly either a +2 if it dealt specifically with rolls about the Fae or a more general +1 to rolls as you've trained them to pay attention to mortal comings and goings as well. Really the effect of such a stunt should depend on what you want it to do. But if you combined this with the Pixie's existing stunt you could get some pretty powerful access to lowdown on what's going on in Faerie.

If you want to lead them into battle remember that Pixies really aren't that dangerous in a fight unless you've loaded them up with a bunch of Aspects for them to tag using maneuvers. I'd say that most of your rolls involving such an army would be Contacts, Rapport, or Resources rolls, don't worry to much about giving Pixies rousing Band of Brother's type speeches with Presence rolls. Just get them hopped up on pizza, promise them more, and point them at something.

Do the other players have an issue with his hoarding? If one of the ways he is saving his fate points is by tagging aspects that others have created or discovered for free then he is also basically taking fate points away from them. I always like to have player created aspects on the table free for anyone to tag, but there is the rule that whoever created or discovered the aspect has the right of first refusal if someone else wants to tag it for the free first time.

Have the other players stop letting him get all those free tags on their aspects on the table. Though it really seems like a unsuitably punitive measure, but he really is messing with the game economy and the other players resources if he does all that free tagging of their aspects.

If you and everyone else have already tried talking to him about his hoarding, what is his response or reasons for his hoarding behavior?

Okay so you are setting the character up to be an apprentice to a PC. Then in that case you should definitely stat the character up as a Shapeshifter who also knows some magic rather than a Wizard who can shapeshift. Channeling and Rituals rather than Evocation and Thaumaturgy, pick up The Sight, discounted Soulgaze, and Wizard's Constitution to show that the character has the potential to be a full Wizard, then Beast Change, Echoes of the Beast, Human Form. That should leave at least 4 refresh at the submerged level, and that's 3 points to buy other powers for the animal form or more levels of Beast Change to mimic changing into some other animal forms.

What sort of animals do you want your wizard to turn into, and how much power do you want those animals to have? If they've only got one animal form that isn't all that powerful than just buying the Beast Change power is the way to go. If you want to turn into an animal or multiple animals with all sorts of nifty powers and still be able to do Wizardry you will need to look for some discounts. Item of Power is probably your best bet, just say the Wizard spent much of his apprenticeship crafting an enchanted animal skin that allows them to change form, or inherited a powerful talisman from their mentor. If you really insist on doing it quickly and with Thaumaturgy (Evocation is right out for something like actually shapechanging) than Sponsored Magic is the way to go, but be prepared to rack up some pretty serious debt to the sponsor.

Out of curiosity if this is for an NPC why are you that worried about the powers math in the first place? A few milestones and they should have enough refresh to do whatever they want, or you could just give them the refresh to begin with. Is there some intent behind this character beyond a Wizard who does cool shapeshifting magic?

Yes there is a Leverage system and it's great. But this game is a mash up of the two properties, it is a crew of supernaturally powered Dresdenverse analogs of the Leverage crew and uses the DFRPG rules not Leverage. The characters are a Focused Practitioner Thief, a Half-Ogre Hitter, a Precognitive Hacker, and a White Court Grifter, the game is a blast. Sorry you can't make it, but I hope that clears up your question.

Noclue, babel, etc: my problem is this. Venomous claws add an aspect and does continuous damage. Environmental effects the gm has in the story can do damage.

If Venomous Claws is what's giving you all the confusion then I think that might be your problem, that is an extremely potent and costly power that should be an exception to the rules not the baseline. It has the same cost as picking up Evocation, Thaumaturgy, or a Sword of the Cross! It is a power that should be reserved for some of the true nasties of the Dresdenverse. The effect of Venomous Claws is so nasty that I wouldn't use it to model normal poison in my games, having a snake bite or a envenomed dart hit a character and I would hit them with a consequence of "SNAKE BIT" or "POISONED" and compel the hell out of them rather than use the Venomous Claw special rules.

Whereas anyone with a little accelerant and a box of matches can set something "ON FIRE". Also most things that you maneuver an "ON FIRE" aspect onto are going to spend at least one of their turns trying to put it out, so that takes up their action for the turn allowing you to hit it again for free with a free tag. Being "ON FIRE" in FATE sucks enough without having to add damage on top of it. It is the same thing with being "PINNED" or "KNOCKED PRONE" folks who have those aspects maneuvered onto them are going to have to give up at least a round trying to get rid of them.

I'd play it by the rules they do work. But if it really bothers you so much I have a very simple solution for you, in your game let them take environmental damage if you feel it is necessary. Ta-Dah!