Android :: Mapping Gestures To Buttons - Possible?

I have a love-hate relationship with my G1, with the inability to remap keys at the top of the list. I've looked high and low for information, going so far as to try to decipher pages like this:http://www.kandroid.org /android_pdk/keymaps_keyboard_input.html and even reading the android platform code on github. I don't see things like page_up and page_down defined in the android keymappings. And I suspect that the original scancodes are being assigned to touch gestures.Since the number keys don't have a third component could an enterprising developer map to the unused caps for missing keys? Not that it would be all that useful at this point but it would give someone a hook to build on. Or if that isn't possible, how about a virtual floating task bar kind of thing (maybe mostly transparent overlay?) that maps gestures like the swipe up/swipe down and more traditional arrows and enter type keys for the trackball? This isn't entirely a nit-picky kind of request. I have a medical condition that in the winter makes my fingertips extremely painful and the trackball hurts. I'm guessing that there weren't many arthritis sufferers on the Android development team, either. You would think that the touch screen should make things easier, not harder. Even my old, old Omnigo and HP100LX had utilities to remap keys, so it seems odd that there isn't some kind of app that could be developed. I think if I had enough time (which I don't) I might be able to eventually puzzle out a crude version of the task bar thing but I'd much rather pay a couple of dollars in the market.