The hardest thing to learn/understand is that tow capacity is a fantasy. It's calculated with a flat trailer with weights and a 150 lbs driver. A high walled TT is like a sail - unlike your popup that sits below it's roof line. Payload is the limiting factor. Tongue weight, WDH/hitch weight, passengers and cargo subtract from payload. Tongue weight can be calculated by taking the GVR of the planned TT and multiplying by 13%. Don't rely on dry weight or brochure weights - they are understated. Your 1500 conversion van is not going to cut it pulling a camper that is significantly big enough for 7 people.
Looking forward to the scale report.