Issues with multiple iPhones using one iTunes/iCloud account...?

I have been using an iPhone 5 since February. Within the last two weeks, two other lines on our family account have started using iPhones (the 5c). All of them are using the same iTunes/iCloud account.

There are a couple of small issues that I can not figure out on my own and I was hoping someone could help me.

First, when I download music, the other two phones are getting notifications from the iTunes store about turning on Automatic Downloads. We do not want/need automatic downloads and I would like to turn these notifications off. How do I do that?

Second, when I visit the App Store or iTunes Store on my phone, I have to enter my iTunes password to make a purchase or download something (even if it is free). The other two phones on my account do not. How do I change that?

I think that is all for now, but I appreciate your help! Thank you!