I assume you're talking about Create Spawn and Alternate Form (Humanoid)? Create Spawn is a gamebreaker, but it would make more sense just to ban Create Spawn from the available abilities.
Here's the thing about Alternate Form: with the way the class progresses, it's coming in at level 14 at the absolute earliest. This is a level when Summon Monster VII, Prismatic Spray, Reverse Gravity or Limited Wish is considered a level-appropriate ability. I am absolutely not
saying that the Student Of The Weird should be getting Limited Wish at this level, let's get that out of the way. However, at that level forcing the character to reset to another progression and get first-level abilities
as his ability for that level (1 point of heat damage! Detect Magic 1/day! WHOO) is a seriously raw deal.
The whole point of this class, as far as I can tell, is to go into the interesting and weird abilities monsters have. For the most part, the "half levels or level 4, whichever comes first" restriction prevents the player from getting the actual interesting abilities and restricts him to more natural attacks and first-level spell-likes with a very few exceptions.