No, no, no and no. Sort of.
It will shoot shotshells, but not well. Shotshell patterns are bad, I've heard, with doughnut holes in the middle. It would not hurt the barrel.
NEF will not drill and tap a Tracker II barrel. Most gunsmiths will not drill and tap the 12 ga. Most gunsmiths will D&T the 20 ga.
The barrel is tapered, not thick and heavy like the bull-barreled versions.
Some have replaced the sights, but I don't know the details.
I have a scope on mine, a 20 ga that my gunsmith drilled and tapped for me, and I like it.
When is the bugout? I'd hate to miss it.