For the most part it looks like you've got the basic grasp of things. There are a few nit-picky things that can come down to personal preference technically speaking.
Firstly I would recommend getting hit cap. This is mostly just so you never have to worry about your diseases missing, which can contribute to your survivability since your diseases are your weakened blows if I recall correctly. And if you have to attempt applying those more than once that's time not death-striking, or building to your next death-strike. It's also a DPS increase which ends a fight faster.
Second, I believe that most DK's are using Swordshattering instead of Stone-skin Gargoyle, this could very well be just personal preference or a fight by fight thing.
Beware Mr.Robot, I don't find it reliable. Now ReforgeLite, I find pretty good, since you can either use their presets for class/spec or you can adjust the values yourself if you're up on haste break points, hit cap, exp cap (numbers not percents, but the conversion is pretty easy) etc. It's an ingame addon and pops up when you go to the reforger. Takes some playing around with at times but I like it.
Personally, I use Stoneskin Gargoyle, but I haven't been tanking that much, but am getting back into it as I need a change from healing and dps. I never really liked Sword Shattering, but that's personal - the disarm reduction in pve is useless and 4% Parry I find meh, would rather have the armor and stam.
Last edited by Theotherone; 04-12-2013 at 02:25 PM.