I can see that about 3, not really about 1, and not at all about 2. Ideally, 2 wouldn't be necessary but I don't see how that approach makes things worse, in particular when the "middle-man" mentioned is accurately described as "unqualified". There isn't any reason the person's conduct (opinion-forming ability?) couldn't be discussed constructively in such an instance.
Personally, 3 is a complete non-starter and I'd just spend my efforts elsewhere.
#2 is like crying to their mommy or daddy when you get told no. You should work it out with the person directly, and if not possible, involve both managers
#1 is all about creating highschool clicks and not a healthy adult behavior. The GP post has a noticeable lack a maturity and experience
If you're at the point where these are options worth considering, then chances are the corporate culture has already gone to shit. The ideal solution in such a scenario would be to find a new job, but not all of us are spherical cows in frictionless regions of spacetime.
Personally, 3 is a complete non-starter and I'd just spend my efforts elsewhere.