If front 2 teeth used to be longer in front and bottom teeth rest behind them. Would dent grind 2 teeth bc of small chip and bonded 1 tooth unlock tmj?

Maybe. There is more and more research in the last 10 years indicating the bite has little to do with the tmj. If your TMJ is locked changing your bite will not help and by locked i assume you mean you can't get your mouth open. To unlock a bite, the jaw may need manipulation with possible anesthesia either in the joint or systemically. I would suggest seeing aa dentist who can diagnose the problem.
Unlikely. Unlikely grinding your teeth would "unlock" TMJ. See an oral surgeon for expert advice.
No. That even may cause more TMJ issue. Try to find a neuromuscular dentist in your area to help you.
Possibly. There are many techniques to change your bite in such a minor way to as to help with TMJ problems and esthetic issues. In many instances these minor corrections will protect your teeth and alleviate pain from grinding and occlusal prematurities. Have your dentist explain what was done so that you can better understand how you were helped.