I main a War, with defiance I heard 10,500 is the optimum HP we can aim for and further adding makes no sense. I have the same problem, I have been working on the left gear getting all the poetics Gear then work on the right getting either slaying of fending

i am heavily thinking of getting slaying for my accessories and push my STR.

1) pushing STR means more damage mitigation and block/parry correct?
2) Would you recommend all slaying on the right?
3) I don't quite understand what does "Only secondary stats have breaking points?" means