Pulling a 25 ft with an Explorer? Possible.
Does the Explorer have the factory towing package already installed? That will usually include the receiver hitch (I think the Explorer's hitch is a 1.25 inch receiver and not a 2 inch, you may have to upgrade the receiver to a 2 inch unit), sway bars, wiring harness for the trailer, and the trans cooler.
You'll want a load-distributing hitch for the trailer, and also a trailer anti-sway control.
Trailer brakes are needed as well, an electric brake controller in the Explorer would be a bit nicer(you can control and adjust the trailer braking more with the electric units) than just a surge brake on the hitch.
For towing, you need to consider the towed weight vs the tow vehicle weight limit, any trailer frontal area limits, and also the GVWR of the tow vehicle. Remember that a weight-distributing hitch (or the tongue weight load) transfers the tongue weight onto the tow vehicle, which would be part of the payload on the tow vehicle itself.
If the trailer has a dry curb weight of 3300 pounds, you still have to have some "stuff" with you. Water in the tanks, propane, food, wife's clothes, flashlights, etc all add up. Don't overload things!
To prevent fishtailing, use a load-distributing hitch, trailer anti-sway controls, and load things PROPERLY (adequate tongue weight is important). Also be aware of cross winds and big-rig turbulence.
If you already can use a 33ft RV, why not just get a dinghy and tow that behind the full size RV?
And about Pydpier's idea of having the wife follow behind with the other 2400 pounds of flashlights, I don't know of ANY car that has a payload capacity of 2400 pounds. She'd need a full-size three-quarter ton or one-ton dually pickup( Ford F250HD/F350, GM 2500/3500, Dodge 2500/3500), preferably with a turbo diesel, to get a payload capacity of 2000+ pounds. The full-size pickups also have a trailer towing capacity of 10,000+ pounds. And if she had that, use that to pull the trailer instead of the Explorer. /ubbthreads/images/graemlins/crackup.gif