I agree with a lot of what you say, and I will even go one further: I believe "going for maximum shield block uptime" is a pipedream. That is that even at maximum shield block uptime and trying to cover gaps with shield barrier, trying to "always have it covered" and going for TDR rules is a bad idea. Honestly I think that giving current tanking mechanics... YOU'RE GONNA TAKE A FULL HIT. Why not gear towards assuming that is going to happen and using sblock and sbar manually instead of automatically as situations required, and having a big huge stock of HPs so that small regular hits don't matter, and big boss hits aren't as relevant.
I said it as a joke in another thread, but I'm starting to convince myself of it:
Stat Priority should be as such:
Hit/Expertise to cap
Gem stam, go for hybrid socket bonuses that give exp/mastery/stam
reforge to mastery after hit/expertise.
Seems like a sound strategy to me. What are your thoughts Krennick?