Why is it asking for my credit card info? I don't want to use my credit card and having other people use it to buy apps, games etc. Is there a way around this?
Haven't done it personally, but one aspect of Family Sharing is that you can define yourself as the admin and set things up so any purchases made through Apple, be they apps/music/whatever have to be approved by you.
I appreciate it might not be an ideal solution for your exact situation, but one of Apple's aims with the Sharing service was to give parents control over what their kids were spending.
My issues with this is my family always shared one iTunes account, this works great and we all only had to worry about one password and username. Now to keep everything straight and backed up we all have separate iCloud accounts. This way everyone shared the purchases and we could monitor the kids apps. If we separate then no monitor and it's a bunch of new passwords. I hope this works with just the one account but I don't see that working anytime soon, Not happy