I am in California. For us, if a buyer has the 'first right of refusal', you can still make an offer, and if the seller is interested in your offer, he has to go to the first buyer and see if the first buyer can match or exceed your term, whther it's price, timing, contingency, etc; does not matter. If the first buyer says yes and delivers, then you will have to wait. If not (they refused), then your contact, after negotiation, kicks in.
Yes, the realtor, and/attorney will need to disclose that that the seller has an agreement with the first buyer for first right of refusal. To protect you, before you present your offer terms to the seller, have them sign an agreement NOT to disclose the terms on your contract to the first buyer. If they agree, then you can present your offer.
However, since I am in California, take it with grain of salt. Hopefully NJ agents will reply to you.
If the second offer is to be a "backup contract" there must be specific wording in the contract to that effect. Also FYI, the kickout contingency mentioned below is just that, it is not a "right of first refusal" or "first right of refusal".
A "first right of refusal" is a clause that allows a buyer to match the terms and price of another offer. This type of clause is usually used in an "option contract." In the case of the kickout contingency, the first accepted offer is not changing their terms and price to meet the new offer they are simply removing whatever contingency was in the contract, if they choose to do so. If they choose not to remove the contingency then their contract is null and void, assuming notiofications are sent etc.
When a buyer puts a contingency in a contract, ie, stating they need to sell their own home first, there is usually a kick out clause(first right of refusal). This allows the sellers to continue to market the property. If another offer comes in that is better, ie without a contingency, the seller has the right to ask the first buyer to either take off the contingency, or back out of the agreement. If the previous buyer cannot take off the contingency, then the second buyer becomes the primary contract and the first buyers contract is removed from the playing field. This is a very common practice.
Keller Williams Realty
Baton Rouge, LA