Forgive me for asking, but, where's the problem?
You have the manual, and the manual gives you a 1500lb limit, and your estimate of the loaded weight is below that limit, so, it would appear to be within the capability of your vehicle.
Having said that - the problem as I see it is not the Tracker's ability to pull the pop-up, but, more it's ability to stop, the pop-up - did you notice the manual says a trailer over 1000lbs needs to have trailer brakes?
The other thing I want to mention, specifically with regards to your having seen Cavaliers & Malibus pulling pop-ups, is that not everything you see being done is legal or safe - I've had folks blow past me on the freeway with trailer attached - I'm at around 10 over the limit, so I know they are well over it; I've had folks blow past me on the freeway with passengers in the tray of the pickup - would I personally do either of those - no - I have a little more regard for personal safety than that. I will take a bet with you, that if you were to look at the owner's manuals for the Cavalier & Malibu you would either not find anything on towing or a statement to the effect that the vehicles weren't meant to be used for towing.
Based on manufacturers' recommendations I'd say your proposal is sound, it's up to you to do it safely, and judging from the fact that you took the trouble to ask, I'm sure you'll be fine.
A couple more points - it might be a good idea to consider an "add-on" transmission cooler, especially if you're going to be towing that pop-up uphill, and I think the manual also mentions a limit on gross combined weight.