The short answer is no, yes, and probably yes.
Under these facts, you don't have sufficient cause to claim a constructive eviction and move out. If you break your lease you will be in breach so that's probably the worst course of action for you. On the other hand, if your lack of proper maintenance reaches to the heat, hot water, toilets working, or structural/electrical problems, if MIGHT be sufficient to claim a constructive eviction.
Bear in mind, under any circumstance, if you have a maintenance problem the LL isn't addressing you are obligated to make your requests in writing and give your LL reasonable time to cure the defect. That's fact-specific, but usually the limit is 2 weeks for most problems. If it takes longer, there needs to be a very good reason (like a part was ordered, or the contractor hired needs to do extra work.)
If your LL doesn't respond in a reasonable time, or provide you information that he is working to fix the problem as quickly as possible (and then follows through) you can send him written notice (I recommend certified mail, RRR for all such communications) that you will hire your own contractors to fix the issues your reported, and withhold rent to the value of the repairs. You'd have to provide copies of your repair bills as proof of the withhold.
As far as your credit goes, if your LL sues you for unpaid rent/breach of lease and wins, he or she can docket the judgment in Trenton and then report same to creditors. In addition, credit reporting agencies will pick up a docketed judgment in their checks (whenever they do them.) The breach itself, however, won't affect your credit. The judicial process will.
Finally, moving away doesn't stop people from suing you. It may give them difficulty in enforcing a judgment, but don't count on it. If there's enough money, successful plaintiffs will go after absent defendants. Without knowing your specific situation, I can't say how likely or unlikely this would be. I CAN tell you it's almost never the right thing to do to flee a jurisdiction to avoid paying for a lawsuit.
The foregoing is not legal advice, and nothing in the foregoing shall be deemed to create an attorney client relationship. If you feel you need to speak with an attorney regarding your issue, it is recommended that you contact an attorney with expertise in your area of inquiry. The information related above is purely for informational purposes, and should not be acted upon without speaking with qualified counsel familiar with you specific situation and the laws related thereto.