#1 - simpaly no - MTA does not support controllers
#2 - Yes, this is simple:
start GTA like normal (single player way), and goto options, change ur controller type back to Mouse and Keyboard and ur able to configure ur mouse to not be inverted in mouse settings.
exit the game, go back to MTA and everything should be fine.
Sometimes the mouse does not hook into the game, and your not able to move your camera once in game - to fix this just hold ALT and press Tab, then left click.
Hope this helps.