I'm honestly not sure what part I should've quoted for that to make sense. I picked the parts that I commented on and left out the portion about some additional toggle stuff that was unrelated.
You want 20 % damage reduction tank stance back with damage penalty while gaining some ability to negate said penalty. Meanwhile in the game right now where the old tank stances are gone we have a trait that gives you 20 % damage reduction without damage penalty which seems to be exactly what you want.
You have the tools to deal with the main tank dying in the game right now without needing enmity combos to deal with that situation. They were removed because they were highly redundant and the current system works a lot better.
The comment about progging was genuine as that is exactly where you'll run into those things you seem to be longing after; dying to lack of cooldowns or lack of heals because something unexpected happed either to dps or healers or too many vuln stacks etc. That is where you get to plan your cooldowns and look for optimizations in your tanking plan. It's just not a big thing in dungeons or normal mode trials / raids which are the same as ever.
Also the point was, that if your suggestion to someone enjoying current tank stances is to go play dps or healer instead then why shouldn't you who obviously doesn't enjoy current tanking take your own advice. Would make more sense to me as it's not like it's going to fundamentally change until 6.0 if even then. Those were your own words.
As for dungeons the only 2 that I can think of where DRK has more trouble compared to others are Bardams and Doma. The jump in defensive stats in gear at 65 is HUGE so unless you stop to gather full sets at that point, the lack of TBN / Mind being magic only hurts there. Anything before that is easier than it used to be thanks to Arm's Lenght and AOE Reprisal being added to the mix and mobs generally dying faster than before. The biggest problem in pre-ShB leveling dungeons for me is lack of mana regeneration in AOE which could be solved in multiple ways but for now it is what it is. I wouldn't mind Dark Mind changing but I'm also perfectly fine with it as it is.
I still don't understand what your problem with TBN is. It cuts into your MP to give you the exact same thing that you'd use during that resource dump for the exact same cost. Calling a basically free 25 % shield lackluster is beyond me.
Anyways, you keep doing you I guess.