The "How to natively remap the Bixby button" mentioned on AndroidAuthority requires you have a Samsung / Bixby account which is annoying b/c I don't want to give my information for a function I don't want. I ended up installing the bxActions app but it requires multiple permissions.
Yep! Just all of the cloud services, like bixby and the such. If you have no need for them then it is not required at all.
Bixby unfortunately is setup such that to disable it the official way you need to sign in, but you can disable it the old way whenever you like and theres no need to create an account.
I've been using my S9 for over a year without having a Samsung account, and I don't intend to create one. What basic functionality requires an account?