I tow a small trailer with my suv.  My trailer is older and a rarity, but this is what I can share:
Definitely get tow mirrors.  Even if you can see with your standard mirrors, you see so much better with tow mirrors.  I just got the cheap strap on ones - I only use them when I'm towing.
You will be unlikely to be able to install a generator.  There just isn't enough storage space to add one and still have room for everything else.  But some manufacturers offer a solar upgrade.
Except for "all electric" models, you will get a house battery and converter/charger.  Inverters may be offered as an upgrade.  
From what I've seen, most hard sided trailers have a regular RV toilet with holding tanks.  Folding trailers and pop ups usually have no toilet, porta potty or cassette toilet.
Anti-sway will be dependent upon actual models and equipment.
Except for "all electric" models, most come with a 2-way or 3-way fridge - it just depends on the manufacturer.  
I love my FoldnRoll.  It's so easy to tow with the Durango.  I find I don't mind the cassette toilet as I can empty it without having to move the trailer to a dump station midtrip.  The fridge is 2-way which works fine.  I run it on elect before the trip and then switch to propane for the drive - I don't have to worry about changing the mode if I make a stop along the way.  I can just stop and leave it on propane and not worry about running down batteries.