Yes, you can use a Dune or PCH “extender” to play BDMV or M2TS files. FWIW, I reviewed a BD Prime a while back and am working on a Smart H1 right now and have been very happy with the results.
BDMV is the whole movie unless you reauthor it. I usually just pull the main M2TS out of the BDMV because I don’t want the menu, previews, etc. but if you want to remux that to remove unwanted content you can.
