Can I disable the GPlay trinity, see what stops working, then reenable?

Or will that make a mess?

I've got most of my required stuff working, so now I need to identify which apps I need to replace or eventually isolate.

Would it be better to uninstall GP, see whats affected, then reinstall?

Also what permissions are default/reasonable for those GP apps?

Disabling it is fine, uninstalling it may break it in other user profiles, although I'm not up to date whether this is fixed upstream.