I am concerned that I may have over tightened the nuts on the 2 toilet tank bolts. I had a slight leak - probably coming from the gasket at the outlet flange - I removed the tank and installed a new gasket but in replacing the tank I may have over tightened the tank bolts. Question: this was 2 days ago and the tank has not yet cracked or leaked, should I leave well enough alone or remove the tank again and loosen the nuts on the bolts?

I would not worry about it. If it doesn't leak, leave it the way it is

Milo

Loosening the nuts may cause a leak. So it will be better to leave it that way.