I cannot answer your questions directly, but theese posts might be interessting for you.
Personally I am running openhab in a docker container on my DIY NAS/Home Server.
My configuration is storen in /var/lib/docker/volumes/openhab-config and I use git to manage and backup the files.
I am not using PaperUI at all!
I started with openHAB when there was no PaperUI.