Lots of thoughts!
I really value the ability to NOT re-meld my gear going from pre-A8S to BiS, so I focused my pre-A8S set on this exact concept. Before I started building a set to use with the Anima coming next week, this is what I would have been building toward:
http://ffxiv.ariyala.com/UA9Y
That said - I know that set is sub-optimal. I'm building toward this, currently, only obviously sub the Anima in where the Midan spear is:
http://ffxiv.ariyala.com/UA9X
Note that both of those sets have THREE Vitality V melds on them - this bumps your max health to 20620 as a Xaela with Flint Caviar, 20743 with Pipira Pira. You can stand to drop one of those melds, but absolutely not all three. 19800 with Pipira is nice, but not for progression. That extra ~1000 health could make or break you surviving a mechanic.
That said, my best in slot is pretty much identical to that, with just the singular change of swapping out the chest piece and turning the VIT melds into actual melds:
http://ffxiv.ariyala.com/UA9Z
Your BiS looks pretty good, though! It's a bit lower weight than mine (by ~2.5 effective strength), but it should work just fine, if you prefer running ~600 sks.