for 1... the more stam you have on that fight the worse it can be. it is A LOT more healing to anub in phase 3 the higher your health is, so its not very efficent.
2... the whole concept of the gearset and tanking all 4 adds is to mitigate as much damage as possible and getting block value does just so. It is just how the fight mechanics work.
3... why would you gem strength?!
edit* Wowhead: OM NOM NOM
search block value/rating gear