Re: Gas tanks!!!
My bike has been dropped, hit, low sided at low speed, and no probs. sounds like your mounting needs work. I use a 1/4" thick sheet of rubber between tank and frame. It's bolted but not super tight; I can rotate it on the top tube with minimal effort. But it will "give" in a mishap.
I don't always listen to Alice in Chains..... but when I do, SO DO THE NEIGHBORS