1) Far too powerful for a single sponsored magic. I count 4 major benefits; Evothaumaturgy powered through feeding which basically doubles the amount of evocation you can cast in a scene, Spell Drinker which allows you to clear stress tracks and mild consequences each time you take out targets with magic meaning you basically have unlimited evocation as long as you use it offensively, the ability to assume additional "Marked by Power" versions, and the mechanical bonuses of armor vs magic and defense vs feeding.
Every singe one of those bonuses would about match the bonuses of any other sponsored magic. I'd never allow them all together. Some of them I'd never allow at all.
2) Do not integrate additional powers into the sponsored magic itself. Simply have your sponsored magic include "Marked by Power", "Feeding Dependency" and "Vampirism" into its "musts".