I can comment a bit on the balance/dizziness issue. There is a possibility that surgically removing the tumor, or shrinking it with radiation, could improve your balance. If the tumor is removed/reduced, pressure on the vestibular nerve may be relieved enough to allow it to make a new connection between the ear and brain. However, those nerves are tempermental; damaging a nerve is not like cutting yourself shaving and there's no guarantee that it will heal quickly or at all.
There is also a possibility that surgery or radiation may damage the nerve so severely that the brain will no longer receive a signal from it. Of course, that scenario is hardly ideal, but it will improve balance by eliminating the "bad information" that the brain was receiving from it.
The last scenario is that your brain will figure out that your right-side ear is a deadbeat and quit listening to it. Again, there's no telling how long that might take.