Well AFAIK that ported ROM is using MM camera blobs, so it has to be better for sure. We would need some driver updates in our sources
I never encrypt my phone, so I can't really tell you. You can always try and report your results here.
Not yet.
In the meantime you may flash a Wifi Direct & Screen mirroring fix from #2. Tested it with Samsung Smart TV and it seemed to work flawlessly. Funny how much mess can one missing config line make. Change on github is here if some developers would need it.