When he mentions torque, he doesn't explain that the 1,000 Nm of the Varg are at the rear wheel and that torque can be changed by changing sporckets or gear ratios.
Yes there have been a few of these submerge it videos with the Stark. And it seems they do survive. My experience with the power switch, the throttle connections under the front plate, and my personal bad luck with the elements would tell me not to do that. Plus, having to snorkel or scuba with a chain breaker to be able to push it out of a lake is not my idea of fun making content ...