Does moon flute need to have a debuff that stops you playing for a while? Can't they just give it a long recast time so you're only able to buff yourself every 2 minutes or something. The debuff that prevents you making any actions altogether feels like bad design.

24 spell slots feels like not enough. Personally I wouldn't have any limit at all and let people cram as many things as they want on their hotbars. It's not about balance because the job was never balanced, I think it's just an arbitrary limit to make it seem less complicated to use. I think the limit makes it more complicated instead because you have to keep changing the set to access different utility stuff.