If changes were being made to the request system, I'd be more inclined to suggest that the request should be tailored to the requester more so than simply creating more requests. I find the whole sex interaction to feel a bit forced already, as I must do it to gain mana rather than wanting to have fun in the sack. The request system further forces my hand by telling me specifically which actions I must chose, rather than letting me do what I want.
Plus, the requests, themselves, never make much sense. Everyone is constantly begging to be humiliated, use their rear, or various other actions that they've never even done before. If a person loved anal and that person continually kept asking for some rear action, well that I could understand. Or if a person was submissive, maybe I could see their constant demand to be humiliated.
Either way, I often get anywhere from 0-5 requests from each slave per series. I find that to be more than enough. I would hate to up the number to where every single turn was nothing but me needing to fulfill a demand. If I wanted all my turns dictated to me I would simply click the button that lets one of the slaves lead the action. Besides, just because a person is not lewd doesn't mean they do not enjoy sex. Perhaps they may be a bit less adventurous, but that does mean their orgasm count should automatically be less.