You can. I'll post a link if I can find it. You can find 12V pumps for $15 on fleabay. I was going to do that when I found this thing. You'll need to add some check valves that can take the heat, and the inefficiency of the Suburban water heater will burn a lot more LPG then this thing.
On the trans cooler, this thing put out a lot of heat, of course, It was the only one in the loop, and the loop was about 6 ft total, But It will work.
Heat will also radiate from the hoses. I had an engine heat loop on the water heater on my GMC motorhome, and it heated up the bathroom while driving, too much, actually.
I'm not sure how much radiator/convector area you can add, but the UK and EU caravans seem to have it all down both sides of 20-ish foot units. This thing heated up the gallon of 50-50 glycol and water I put in it really quickly.
I'll measure the Amp Draw when I get home next week and play with it some more, but IIRC it was less than 2A total for the whole unit. Less than 5-7A for the blower types.
My next test will be plumbing some PEX around the bed frame to warm the bedroom radiantly from under the bed.