It was a bit rough in the beginning I admit. I’d recommend giving it another try.
You can look up this thread that has an updated tutorial.
https://www.reddit.com/r/revancedapp/comments/xlcny9/revanced_manager_guide_for_dummies/
Very easy to follow and should get you going.
Are you thinking of Vanced? Revanced has been steady ever since I switched almost a year ago.
I usually use slavart, but it’s been unstable lately. With it, you can download anything from Deezer and qobuz.
In Smarttube, go into settings and link device or something similar (edit: remote control). On your phone, go into settings and link TV and input the code Smarttube will give you.
It acts more as a remote, you need to have Smarttube already opened. It’s not perfect, it’s a decent compromise.
Same for me. Smart audiobook was great on one device, audiobookshelf even better since being into selfhosting.