Dude! I'm a gringo but listen to me carefully!
My wife is from Xela and we have been back 4 times in the last 2 years so I'm speaking from experience.
The 1st order of business for us when we get to Guate is to get out of the city asap! It is just too dangerous. I also want to retire to Guatemala, but she doesn't, she says it's nice to visit but to actually live is just too dangerous. It's not a question of IF you're gonna get robbed or worse, just a question of WHEN!
If you really want to live there, I suggest going for 6 months then reassess whether or not it's for you. The traffic is an absolute nightmare. That road that lead out of the city to Xela (I don't know the name of it, it's the road that goes to Tec-Pan) gets backed up for miles in the morning and afternoon. The smog will have you coughing up phlem constantly and your eyes burn from all the black smoke that blows out of the buses.
Panajachel is beautiful, but it feels kinda shallow after awhile, tourists are everywhere and all the stores are selling "trinkets", basically junk made in china passed off as authentic mayan artifacts. It just feels sad to me, the beautiful mayan women trying to make a living selling chinese crap to fat white people is depressing to see if you look at it for too long. Even if you go across the lake to other towns you are immediately met by little girls with trinkets begging you to buy from them. If you live thete you really would feel obligated to get involved to help out in a more meaningful way. Just going to work and live would get old FAST!
Stay here and work and save your dolares and go down for a few weeks each year and volunteer in some way. That will scratch your itch to be back in your pais.
Good luck and maybe we'll meet down there someday.
Your friend the gringo from reddit.