Hit any pot holes recently?? That would definately throw off your alignment and possibly even throw a wheel out of balance.
You should check your front hub assemblies as well, to make sure they turn smoothly. I'd eliminate all possible mechanical defects outside your transmission before tearing it out looking for something that might be elsewhere. Check also your motor mounts I'm not real sure what weird feeling you are getting from your gas pedal. Basically just give your car a very good once over and have the wheels checked for balance. It's very possible you lost a wheel weight while driving down the road minding your own buisness. It never hurts to check it out before you go tearing into things.

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95 Eclipse RS - Rolled
96 Eclipse GS - Traded
95 Eclipse GSX- Sold
01 Blazer LS 4.3/5spd dropped and clean DD
88 Camaro RS 361 CID with a 6spd and a bar 10 second street car on motor.