That is correct.
Yes, but org-roam-server needs to be updated for the new db schema.
Issues with processing large org files still remain (for now), but it will support the structure.
Yes, Tags will be specified via Org tags (and FILETAGS for file-level nodes)
Unaffected. Org-roam duplicates that information, and can choose not to use it.
I’ve personally been using the V2 branch for a few months now and making changes where necessary. Works fine for the minimal subset of features I rely on.