- Does the net weight in www.nada.com accurate?

Probably.




Does it include a trailer?

No. Add 1000-1500 lbs. (That sounds about right for a 26 footer, so it
almost certainly is net weight without a trailer)




What does the "net" mean in net weight... what is the "gross"
weight?

Don't know how NADA figures it, but gross weight should be empty (boat by
itslef), net wt should be loaded.(fuel, gear, etc)




- Is it a very bad idea for me to try to tow this baby with my Volvo?

Yes, a very bad idea IMHO. Your Volvo dealer would probably refuse to
warranty a repair because of the overloading. Need a fairly large truck for
that. Our 01 Suburban (towing capacity around 8000 lbs) might do it, but I'd
still get something more muscular, depending upon the terrain in which you
will tow it. That's a big boat to be dragging around.