Yes NJ has implied consent, that being said you may still have a defense if you are charged with a DWI but to determine that you need a lawyer to review your facts and charges.
Yes. Refusing to submit to a blood alcohol test is its own violations, with basically the same penalties as a DWI conviction.
Yes. If asked by the police you must submit to a breath test or you will be charged with a refusal.
Yes, all states do. Here is some info:
Implied Consent. ... New Jersey's “implied consent” law says that if you are lawfully arrested by an officer who has probable cause to believe that you have been driving while intoxicated, then you consent to taking a chemical test of your breath for the purpose of determining your blood alcohol content (BAC).
https://www.newjerseydwiattorneyblog.com/2011/04/implied-consent-warnings-in-ne.html
