So I just got my used Rockerverb 50 today and noticed that the power cable input socket on the back of the amp seems to wiggle back and forth a TINY bit. The cable that was shipped with the amp seems to fit a little too tight, so I am guessing that this cable being connected and disconnected over time has possibly loosened the socket. Should I have this looked at/tightened by a tech or do it myself? Does that even need to be done? Its not giving any issues so far, so should I even bother with it?
A little wiggle now means a lot more wiggle later. Personally, I would have a tech look at it. Unless of course you know how to fix the problem yourself.

Don't let your gear go astray. Get the problem corrected early on before it becomes much more costly later.