OP, I share quite a few of your criteria when it comes to potential retirement places. Of the places you listed, Denver would be my first choice.
You might consider Reno. Close to Lake Tahoe and the Sierras. Go in the other direction and you've got the mountains and high desert of Nevada. Tons to explore in every direction. Weather is pretty decent -- sunnier and less snow/rain than Denver. Good-sized airport with flights going to lots of places. And the Nevada tax breaks. Doesn't have the food scene that Denver does, but it isn't terrible. The politics there tend to be more moderate than much of the rest of the state.
I've also thought about Albuquerque. Even better weather, somewhat larger than Reno, and a decent airport. Pretty good food and beer scene. But Albuquerque has some pretty sketchy areas and crime can be an issue. You definitely would need to pick the correct neighborhood. Quality of health care would generally be better in either Denver or Reno (or lots of places, frankly).
Tucson checks some of your boxes, but it gets really hot in the summer. Not as hot as Phoenix, but pretty damn hot nonetheless. They also apparently have infrastructure issues there from what I've read.