Thats true, once I found that pitch mechanic in godot I used it for a lot of sounds. Yes, the sound design is a whole new world of its own, it's actually one of the last things i've dealt with and lost myself in. as you rightly pointed out, there will be a lot of changes there.
Yeah my balancing is constantly swinging between too hard and too easy I'm just trying to get a feel for where the sweet spot is, and I think I've playtested my game way too many times myself which has made it even harder, so it's even cooler to hear your words of support. It really helps me a lot!
As for the powerup mechanic, I'm thinking about redesigning it anyway for the very reason you mentioned because it can go from too hard to too easy very quickly.
Thank you for your feedback!