Understanding ACL and Groups with phpBBAuth

[graveeater]

I'm using phpBBAuth as an authenticator.

Now I'm trying to understand how this impacts groups. And maybe ACL.

As far as I understand, by default, all groups from PhpBB are available (given that there is a user who is in them).

Are they available in all channels?

If I define a mumble group with the same name, will it overwrite the phpBB group?

If I exiplicitly remove users from one of these groups in an subchannel, will it work?

Are groupnames case sensitive?

Does whitespace in groupnames matter?