I distance myself a good amount and the airbag still felt like being punched in the face. Guess it all depends. My girl is 4'11''-5'' and she sits sorta close but she just leans the back rest part further back. If you do that you should be fine. It's better then the alternative I suppose (hitting your head on your steering wheel/windshield).

But I'm still not a firm believer in airbags but in your position I would say keep the airbag. For people who sit further back I would honestly say the seatbelt is good enough. The gas from the airbags tend to burn people's skin, eyes, and the impact feels about the same as hitting the steering wheel. I speak from experience.