From what I can tell, the only mechanical parts of Aizawa's human mech are in the skull. She basically becomes one with the suit in sensations and needs. In other words the suit can get drunk and she also gets drunk from the link between her and it
1. There's a limit to how dumb you can be not to realize what's happening here. 2. Kiyomin sensei is somehow not fired after a long history of exhibitionism.