The other thing to do should already have been SOP. Loop your cable through the cab handle before inserting in the amp input. Very much harder to do any damage.
I think with the class D stuff you mostly have to eat the fact amps aren't that fixable anymore. That's not to say they can't be fixed but it often involves spending more than they are worth.
Even more reason to buy a lightly used one and hope for the best. Save some more for a spare you can leave in your glovebox.
If there's jamming involved I prefer the right side for a righty guitarist and left for lefty so I can see what the chording hand is doing. I can't actually read guitar chords I do it by osmosis.
Tempo problems can be very much more subtle than "player X is rushing causing everyone to speed up".
In anything that has a swing to it there only needs to be a slight disagreement over how much swing is the right amount. If the lead swings in ahead too much for the drummer's liking they may 'catch up' to correct the amount of perceived swing. The bass hears that as "everyone speeding up" and all of sudden the next swung note has done the same and you're off to the races.
I took to indicating the tempo with my foot and swaying so the drummer can pick up on it subliminally.
It seems to be working. He used to be all over the place but since I started my little routine he almost never gets it wrong.