Hi, J ~
Sorry you were diagnosed with an acoustic neuroma but glad that you discovered the ANA website Discussion Forums.
I'll attempt to succinctly address your questions.
Avoiding facial paralysis as a result of AN removal surgery is always a concern. My neurosurgeon opted to 'debulk' my 4.5 cm AN (peeling off layers) then use radiation to destroy the remaining tumor cells. It was very effective. So, there are options but that is a conversation you need to have with your doctor.
ANs can grow back after surgery and/or radiation but the re-growth rate is small, about 5%.
Skull-based surgery is hardly routine but medical knowledge and new technologies have made it less riskier than it once was.
The Translabyrinth surgical procedure does guarantee hearing loss in the affected ear.. Retrosigmoid may save hearing but the odds are fairly small. The Middle Fossa procedure has a good chance of preserving hearing but there are no guarantees. These surgical approaches are determined by the size, configuration and placement of the AN and are the doctor's call, although you, as a patient, can always reject a doctor's decision and seek another physician.
Losing part of the mastoid bone is not a big problem. I occasionally get an ache in that bone but one Ibuprofen tablet knocks it out.
My suggestion is to do your research and don't simply accept whatever a doctor tells you as your 'only option'. Also realize that thousands of folks have undergone AN surgery and done just fine. I'm one of them.
Please try to keep us updated. Thanks.
Jim