I have a tier 2 shadow warrior and have helped my nephew with his tier 3 shadow warrior setup so I know a little about the class. I agree with you that SW could use changes, but I'm wondering if a SW simply isnt your play style.
Logically then, we are a threat at any distance right?
WRONG!!
I don't think it was their intent to make the shadow warrior a threat at any distance so don't get too upset. Assault is going to be semi useless unless you have a pocket healer so I'd say SW is a long range class. However, a SW has a few more advantages over a BW in short range situations mostly due to assault stance. BW has a aoe root and a temp armor boost while a SW has the aoe root, permanent armor boost (assault stance) and disable, interrupt melee strikes (assault strikes), and take down (with tactic slot for 5 seconds!). It's a much more balanced mix to stay alive longer in close quarter situations.
Here in lies the contradiction and ultimately the failing of the SW class. That is our tree's are directly tied to the stances. While we boost one tree, we weaken the other stances making our class mechanic a useless mechanism to us. And then to make matters worse, our tactics benefits trees and stances almost exclusively. Why would one use a tactic that increases crit chance while less then 45 distance from the opponent while in scout stance and assault tree specced?
The tree issue strength applies to any class really. Just a SW has the extra step of switching stances which really doesn't take up too much time.
I don't think assault should be a tree to bother with. There's typically a tree for each class that people look down upon. For engineer, its the tinkerer (although I like it), BW is the incineration (although I like it too). WP is wrath (although Kut likes it!). Play styles and preferences. Assault is a path for those who want to play against the typical spec grain, I think.
Regardless, I hear what you're saying about a tactic assigned to a stance that limits it. It would make sense for them to lift that restriction in the tactic that you cited - atleast between scout and skirmish.
The very use of our class defining mechanic ultimately makes us useless. If you are skirmish specced and have tactics slotted for skirmish and you are forced into mellee range and switch to assault stance, all you gain is double the armor but none of the benefits of the assault tree or assault tactics.
I think the point of switching stances is to use an ability in it. For example, if you are specd for skirmish, you may want to start out as scout to get the armor debuff, and then immediately switch to skirmish. That's how I'd play it. Switching stances to one that isn't your spec is situational.
I don't think anything I've said made sense to you or you disagree because I think you just don't like the class no matter what. So are ya gonna try out a Slayer or WP or something?