Yeah, I've played an Incantatrix without an item familiar. Pumping Spellcraft was not a notable challenge. I mean, for one thing, you're a buff persisting class. If you can't figure out a way to boost a skill check, you're doing something terrible wrong. You're also an int based SAD class. This is an int based skill. If your int is not great, you've been doing something terribly wrong. And, as a wizard, you should be keeping Spellcraft fully trained by default. So, it mostly takes care of itself.
If a player wanted to take an item familiar, the xp bonus would be right out. I'd allow some skill point tricks and the like, but not target the item familiar really unless the player did something ludicrous like waving it in an enemies face and proclaiming that it was the source of his power.
I wouldn't allow it as written...but I feel like everything in UA is stuff that you should pop by your DM before using, so it's not a big deal.