Wang -
Not "all regional airlines suck". Maybe you've been bouncing around between jobs too long to settle down and build up a little seniority to enjoy what you are doing. Starting over at the bottom sucks. But eventually you get over it, usually.
If hot weather is the reason you're wanting to go to Mesa, why not check out SkyWest? It's definately hot in SGU. And I'm forecasting another new-hire class shortly.
Sorry you're not getting the answers you are looking for about interview questions... but if you had asked about SkyWest, I'd have said the same thing SKC said. There's no secret interview questions that one dispatch manager asks that another dispatch manager doesn't know about and ask. Know the FAR's and weather with regards to flight dispatch for the test. The interview is an interview.