I think you might mean the engine was too rich, unless I'm still misunderstanding...where is the fuel pissing out from exactly? There's nothing you can do if your internals of your engine are scarred, except replce the damaged parts. I would suggest to just get another cheap .12 engine and tune it a bit more carefully this time.

As for your wheels, no they shouldn't wobble too much, check the rods and ball ends in the steering system for bends or looseness, and replace whatever is necessary. Have an experienced person check the car over for you, as it doesn't sound like you have the expertise to successfully diagnose all the potential problems you may have. Of course I mean no offense by this, I had a ts4n for my first nitro car and I also destroyed my engine and crashed it plenty.