garci, I know a couple of guys who work for SGPD and they seem to like it, but I've heard the testing process is kind of long. I believe they have a pretty good policy for paying you for your education since it may be tied to promotions (an AS or AA degree to test for Sgt, etc), unless that has been cut due to economic reasons. SGPD seems to fall between big city and small town departments. Some guys come from smaller depts for a step up and others use it as a stepping stone to a bigger dept. The sheriffs dept website will give you an idea of the level of criminal activity in southern Utah.
https://news.washeriff.net/bookings/ They list the past 48 hours of bookings. It is entertaining at times. Even better when you see someone you know.
Your wife will probably be able to get a job as an RN and I think the schools are good. Obviously, as a police officer, you will find out quickly which schools and nieghborhoods are better than others before you buy a house. I have my preferences but I will let you figure that out for yourself. If you and your wife are willing to put some time into it, there are plenty of activities to keep your kids busy at school and in sports.
I read this site occasionally and comment rarely, since lots of questions start off with 'I'm not a Mormon, will I fit it?' and several posters offer answers that seem to not even live in St. George.
Anyway, St. George is a good place to live but it's not without it's problems, like everywhere else.
Good luck with the testing process.