WhoTheFuckisAlice To be fair, I don't think anyone approached or treated you like a troll, I think people have been generally open and trying to help address your questions since you've been used to handling things in a different way in the past, so a lot of things seem new to you. :) Sorry if you've felt in any way unwelcome here.
Regarding contact scopes - here's the easiest way to describe the feature:
You know how apps sometimes need the contacts permission? On other OSes, you have the option to allow them access to your contacts, or not allow them access to your contacts. It's all or nothing, and some apps can even not work if you don't grant access to your contacts.
With contact scopes, you can make an app think it has access to all your contacts, but you only grant access to specific contacts you choose. The choosing process is done through a contact picker using the contacts app, which is why it's important to not disable it.
For the phone app, I would use it and not replace it for two reasons - I wouldn't want to extend trust to another app and would rather use the system, and the system dialer has call recording functionality which cannot be implemented in 3rd party apps, so if you want call recording, you'll have to use the one that comes with the OS.