Are beavers pretty territorial, and also protective of their territory from other beavers 'infringing' upon 'their' territory?

Insanely so.

Yup.

YES, , why do you think they respond so well to a non colony beaver scent on a castor mound?

Farther north you go, the more territorial they seem to get.

Muskrats too...you outta see how high the muskrat droppings on an artificial castor mound gets when you get a good flood if a beaver doesnt hit the mound and smear everything back out.

Beavers will tolerate former members of their colony more so than complete strangers. You can easily see this in a completely unilateral water feature like one river system that has no tributaries.

Beavers move up and down the river to mate and colonize. Their former colony will recognize them.

But buck-toothed Billy the beaver from the next river might tote a butt whooping from Bobbi Jo and the backwoods boys if they smell a stranger.

Yes, that's why castor lures work so well.

i have one down back plugging a pipe nightly that is about to get territorial with the mud on the bottom of the pond if he don't quit.

You already know he ain't gonna quit. The sound of running water hurts his ears! Lol.

i know,he will need lead persuasion.

Peekers, just bite his foot a dab and show him the bottom of the water.