A biggie is to blow out the microwave control board,
Yep - been there done that - in the US - $138 parts - and my labor learned watching You Tube - not an easy fix on a built in unit - but where would we get parts if it happened in Mexico?
Any idea how often you have to pound in the rebar for a ground?
Not very often because I can usually find some way to ground - I do have a 4 foot smooth metal rod (not rebar) that I can get in and out easily but it is probably not the best ground though better than nothing - and yes water is added - I limit power use when ground may not be adequate.
I am not a trained electrician though I did work with electricians and have studied electricity and household wiring quite a bit over the past 50 years - and also back 50 years ago I was trained as an electronics technician with very intense 6 months by the US Navy. Meaning I do have some understanding of electricity but am by no means an expert or really qualified to give a lot of advice. I always suggest further research and training to anyone who wants to mess around with electricity. The point of my post was to let people know there can be problems with electricity no matter where you go - this based on the survey or poll done on the referenced website - the guy who does that writes a lot of stuff about all of this and people can learn more by linking to a whole series of articles he has done. I only add my two cents because we have some experience with how things work for RVers in Mexico which can be different than the US experience.