I would agree with shimms. It sounds like you're wrestling with security vs. opportunity. Sometimes jobs that provide that stimulation/opportunity fall into your lap, other times you have to take a leap of faith and see how it plays out. The decision becomes harder depending on your personal circumstances (e.g. family, etc.). But even then, people move across the country to pursue opportunity, even if it means uprooting your family. Just don't be fatalistic about it--i.e. if it doesn't work out, then all is lost. You will have learned new skills and something new about yourself that other people don't have the guts to pursue. Good luck!

I am fairly young and don't mind moving to a different state.

My next questions would be: What should I demand that will make him more obligated to keep his end of the bargain?

Is there a way that I could figure out whether the hiring manager is being genuine and not a used car salesman?