Ok, I have understood the meaning of these questions, however the answer is yes only to "Can you access the host filesystem transparently from within the 68k applications?" and "Can the 68k applications communicate via ARexx?" (but within them), for the rest, you have to wait a smarter version of E-UAE.
AmiBridge is meant to allow people use 68K apps to do tasks that AROS doesn't allow to, for the moment, because there isn't yet a proper application. If you want to keep using your 1989 software the way you used it in 1989, just use your 1989 computer.