Try using teflon/plumbers tape on the bb threads , it will stop things working loose and make your BB a little snugger.

The pop/click sounds like a BB adjustment issue, which you seem to have discovered is caused by your BB being loose. If you're still getting it when everything is snug then its a bearing issue which means replacing the bearings or BB.

I would also check your adaptor sleave/cup is not cracked. Some of the cheaper Sealed BBs have plastic ones and it can be damaged if not installed correctly.

Good luck