There are 10 recruitable maids + Cleo (guitarist) in the maid cafe. As for the gym bug, I think Anvil is aware of it. If you don't want to wait for the new version for the fix, you can find my post below regarding how to fix gym.
Total of 12 people there, but Cleo is recruitable but not really a maid, and Tasha already works there before you do any recruiting, so yes a total of 10 maids that can be recruited.
