And even if we did get together and tried to so stuff, the average Joe is just going to call the cops on us, or shoot at us or drive a truck into us

in my experience that just isn't true in a lot of places/situations tbh

I've been threatened with a gun (that was never produced and probably didn't exist) and yelled at (ironically the guy thought we were anarchists and shouted about how stalin was right and we should all be shot) and cops called (if you have a large enough group, they won't be able to coordinate a response on short notice very well and may well just leave you alone or come and impotently complain at you before going home), and it's never worked to stop the action (not to say it never will, these were low stakes actions, relatively speaking, but still)

major support for just doing stuff and seeing what happens, you can achieve more than you think before the repression really kicks in, and you'll learn a lot very fast.