I don't know if this has been mentioned because I haven't read through the whole thread so if it has I apologize for the double listing but my perfect place for you would be PRESCOTT, AZ. Everything you've asked for including no natural disasters and some beautiful red rocks as well. Check it out: Prescott Arizona Chamber of Commerce
Prescott is about 2 hours from Phoenix but it's straight up the mountains and has beautiful 4 season weather with little extremes. Plus it's large enough to have all the medical, shopping, etc. that anyone would need.