S2Charlie

Ok, so I just got dune putting in my new exhaust... what a PITA! Anyways, I start the car and i realize my driver side airbag light is on... I'm pretty sure it's been on since before that but I never let it bug me. After reading a few posts I realize that if I do get in an accident (god-forbid) the airbag won't deploy (cause the error light is on) there are no Error codes BTW. If I go to Ford, will they tell me I'm screwed (see mods below) or will they honor my warranty? Or does anyone have any ideas? I am missing an 02 sensor on my cat but I don't see how that could cause it, plus, I'm pretty sure it's been on since before I changed it. Also, if I put the car back to the stock tune (disconnect battery) before I give it to the dealer and they drive it will it fudge my engine up (the CAI instuctions say DON'T DRIVE YOUR CAR WITHOUT A TUNE) I don't know if they mean at all or for many miles... Someone PLEASE help me out here... I know I asked a lot of questions so in summation

1. Is my warranty shot
2. Will airbag not deploy
3. How come I get a warning light but no code
4. Could it be related to the 02 sensor (pretty sure it was on b4 that)
5. If I reset my ECU to try to get service will my car get screwed if they drive it