I really like the idea of a magical apprentice as an alternative to a familiar. Consider the concept yoink-ified.

As far as the class goes, a Spells table would be awfully handy.

Charisma modifier per spell level of spells known.
At the beginning that's pretty neat, but becomes very strong towards the higher levels, but then again I've never liked the extreme limitations on a Sorcerer's 9th level spells known. Then again 8+ is a lot, also, how does this interact with temporary boosts? Get a spell of Eagle's Splendor and does the sorcerer gain extra spells known? Do they change every time the sorcerer gains a temporary boost? What about with a continuous magical item?

9th level spells by level 20 feels late.

Its not something I would use, personally, but it looks like an interesting take on the sorcerer.