Just an FYI "security" cameras don't accomplish ANYTHING, I've had stuff stolen and have heard reports of other people having their stuff stolen right in front of cameras and they have never stopped or helped getting anyone’s stuff back.
As for the trailer there isn't much you can do to stop a determined thief, if it's a trailer that's sitting in one spot for a period of time they will simply case it and bring what they need. All you can do is put as many locks on as you can in the hope they move on and pick an easier target. I use the coupler lock but they could still just unbolt the coupler and use another one. I also use the cable through wheel and frame, but like the others have mentioned it would probably break or they could just drag it down the road, lol.
Just make sure it's insured, if your home owner’s doesn't cover it, I would think it would be pretty cheap, A LOT cheaper than $100 a month.
my .00002
fitz