User creation with Active Directory

Hi guys, I have a recent NomadBSD, installed into Virtualbox upgraded to FreeBSD 13.1 and I activated login via AD/Winbind, basically following this tutorial: FreeBSD: Setup Samba as an AD Domain Member – Blog of Kliment Andreev – A place so I won't forget things

Login works but I’m struggeling a bit with the permissions necessary to make an AD user a fully working NomadBSD user.
I tried to rebuild what the officail user creation tool does (as it doesn’t accept “@” in user names) but that’s a bit cumbersome.
I can basically use the AD users but there are still error messages, e.g. from VBoxClient, which seem to come.from missing (file) permissions, e.g. in the home folders.

So my question is: Does anyone know (and can explain in a few words / supply.a link) how the whole user setup works? Basically: Make sure a n AD users gets…a), b) c) . in order to use the desktop.

Thx in advance
Betzi