Firstly, maybe its just me, but when i read the thread title i thought the post regarded something completely different. For me the term "twinking" reffers to experience locking a toon at a level lower then max and filling him with best in slot items for pvp.
As i dont play a warrior (paladin here), ill overview a few questions i think i can help without entering specifics as other forum viewers might cover them best.
"which is adding dodge % + parry % + block % and lastly adding the shield block value)"
I didint quite understand what you did here, but i beleive it is incorrect. You seem to have stated to add block twice, once the percentage and then the value. This makes no sense at all. Full combat table coverage (or unhittable) would be pushing unmitigated hits off the combat table, and the amount blocked does not affect this calculation.
As mentioned in other posts, your total combat table coverage is 5% miss+dodge% + parry% + block% (i think NE get a +2%, im shaky on that though). Note that this percentages must be added alweys *after* DR.
Your CTC is roughly around 84% (i did the math by head, so it surely is inprecise).
Note that at your item level, as a warrior, it is *impossible* to acheiv "unhittable" (first thing that tipped me you were calculating wrong), but this does not affect the value of mastery.
There is no mastery cap. Mastery is not affected by diminishing returns and hence why we (warriors and paladins) stack it.
it loses some value however for warriors once you acheiv 102.4% table coverage (all to paladins since we dont crit block).
As to consumables, with experience you will learn to switch to the most apropriate acordingly to fights.
Steelskin flasks are alweys nice. Progression raiders often opt for more expensive use of elixirs (used up on each wipe). This is detail to some extent, if your raiding casualy i consider just poping a flask fine.
If your interested in the extent of options i raid with stacks of
-elixirs of the master (mastery elixir) - to hit ctc (paladins hit it before warriors).
-prismatic elixirs (magic damage)
-the armor ones you mentioned (deep earth?)
-elixir of the naga (expertise - boost dps/threat- im only using these on alysrazor atm)
-varied food buffs (expertise/stamina, mastery/stamina, dodge/stamina).
-varied potions (golenblood, armor pots, health pots, magic resistance pots)
Chosing which to use depends largely on the boss you are about to fight. More magic damage fights might need some extra magic resistance consumables, largely phisical damage fights point to mastery/armor.
Personaly i havent felt need to prepot golemblood on most pulls.