Well there isn't any limit placed on the number of questions you can ask or answer on musing per say, but the amount of RCs that you have plays a vital role in determining just how many times you can comment on steemit or any steem related Dapp.
If you have up to 100sp then you'll be able to answer and ask up to at least 100 questions before your RC has finished and that's more than enough if you ask me, besides, RCs take about 4 days to fully recharge so you'll be fine even if they finish.
I've probably answered far more than 100 questions on musing and I haven't had any issues whatsoever so I'm pretty sure there isn't any limit. If you really want to be sure then you can go to the musing blog page on steemit(steemit.com/@musing), There you'll find a link to their discord server. You can join and ask the admins there yourself, they're quite friendly and will attend to you quickly.