Stop other devices ringing

I am reaching the end of my tether with this ridiculous icloud/facetime syncing. Yes, my wife and I share the same Apple ID, but why not??? We want photo sharing and a joint ID to sync purchases across devices, but i don't want them all to ring when receiving phone calls, irrespective of source.

I disabled cellular calls within Facetime, but this had no effect. They still ring!

I have turned off Facetime on every device. They still ring!

I have turned off Handoff on every devise. They still ring!

I have logged out of iCloud and then re-logged in. They still ring!

ARGHHHHHHHHHHHHHHHHHHHHHHHHHHHH!!!!!!!

Why would Apple assume we want this feature on, as default? Yes, it may be useful to a small minority, but to the population at large, it's pointless. And, why make it so ridiculously hard to turn off?

HELP PLEASE.