With all due respect, you are about to make a huge mistake. And possibly a tragic mistake. The fact that you should have 1000# wiggle room, which is not there, or a certain percentage of your GVWR, which you don't have, you will be putting yourself and others in serious danger. I'm not being picky or dramatic....the responses you have gotten here are from people with experience. Whatever the salesman told you must be taken with a grain of salt. His job is to get you to sign and then the problem is yours. Many will tell you what they think you want to hear.
All of us would love to tell you you're fine, go pay the man and start camping. The truth is that you're nowhere near safe. Our old camping buddies had a ROO 19 and towed it with a 6cyl Toyota 4-Runner, well equipped AND within the noted specs. They used it for one season and traded to an 8cyl. Let's assume you don't have a terrible accident caused by too much trailer towed by not enough tow vehicle, you most likely will be replacing the tranny or more very soon. Additionally, if your insurance or the law enforcement find that you knew and ignored the fact that you were not within safe limits, you could be in big trouble. I hope you will reconsider this.