Since the new walls have been made, the fiberglass/aluminum/Styrofoam, trailers and motor homes have become considerably stronger. Older ones not as good, but as Ozarker states, should be good enough for your adventures. The number one problem becomes you growing with confidence in your abilities, the trucks abilities and then the trailer. Most that have trailers fall into two categories. I want it sound and really have no desire to do the Rubicon with my trailer. KOA, state parks, National Parks, trail heads by fire roads are their limits and live with in them. The other side, challenges him/herself, their tow vehicle and the trailer. The second group are the ones that may require more than just a off he shelf popup.
Unfortunately for us in the west, that is what our trails are. Our mountains are treed, but not to the level of the Ozarks or the east coast or even Colorado. More sparse with rocks and narrow trails to over come. Sharp rocks, severe drops offs and lips to climb up and over. Twisting, turning, drops and hard steep rises, put a tremendous amount of stress on the trailer... The other option for us is wide open desert trails, and high speeds across washboard and deep holes. The larger tires are for those reasons. Having the same tire on the trailer helps with flat situation. I have had two flats in one short trail run. Carvacre trail.
http://aspenxtrails.com/videos/
You need to figure what type you are, you will either fall I love with the trailer and use it until the wheels fall off, or decide it is more trouble than it is worth. Most that use these things, it has become a way of life. Or it is a necessity for what they do.
From your comments again, I think any popup will work fine for you. The manufacturers that claim to make both, really are not that much different form highway to off road. IE the main manufactures, Fleetwood, Coleman. They just put larger tires on them, a larger drop on the axle and some fiberglass/rubber or diamond plate on the front. Nothing structurally is different.