General understanding about OH2 concepts

I am currently trying to migrate my OH1 to OH2 and obviously there are these new concepts I need to get my head 'round. (using the offline version, cloudbees/Jenkins build #84)
So I started with adding new bindings and removing unnecessary ones via paperUI

The log files tell me that the bindings were removed, yet the paperUI still shows it as "available " under Extentions/Bindings and I can still configure it under Configuration/Bindings. ->Bug?

The new installed Bindings (mostly 1.9) I’d expect to show up in the addons folder, but this remains empty. Yet there are individual conf files created under /conf/services. ->expected?

The Sonos Binding is the only 2.0 binding I am currently using. Via paper UI I’d expect to be able to do all the configuration via the webUI, but I can’t see any of the configurations take effect in the things file. ->where do I definde which thing file to use?