I strongly suggest you do some basic research before you go around claiming that "most" gang bangers, etc. are obtaining their weapons legally. That is absolutely false. You want to control crime in high crime areas, get the state governments to pass laws which keep violent criminals off the streets better. Limiting the ability of honest citizens to legally obtain and own weapons has done nothing in the past to curb crime, and there is no reason to think that will change with more strict gun control laws. In short, no, I do NOT agree that crime rates are a reason to enact gun control which restricts ownership by law abiding citizens.
As far as importance of issues, I say again that is up to the individual. You have you hierarchy and I have mine. Limitations on constitutional rights are at the top of my list. That includes 2nd amendment rights and it includes 4th amendment protections against warrantless searches or wiretaps. And it includes 14th amendment protections of all living humans.
Economic issues are important, but like I said before, economies fluctuate, and both parties have policies which help and policies which hurt the economy in the short run and in the long run. I try to support policies from a Hyppocratic approach - do no harm. That's why I liked Bill Clinton on the economy. Other than his mis-timed tax increase, he pretty much let the economy run without trying to tweak it all the time.
But over all issues I would rather risk a bad economy than risk our constitutional rights.