So my understanding is that by "chang[ing] static spirit to match what your gear can do", you mean that I should just allow my spirit levels to scale up naturally with gear level, only keeping the spirit I get from green gems in blue sockets and what occurs naturally on my gear? Is there a point at which I should start reforging out of spirit? My guess is only when I feel like I have a surplus amount of spirit and the 2nd BP is in sight, and I could comfortably reforge some spirit into haste to hit that BP?
And my final question is if in your opinion, is a Mastery focus probably ideal in my situation? From what I have read Mastery synergizes especially well with resto druids and disc priests, since int helps us to fill a more resto druid-like role with stronger HoTs (therefore to avoid conflicting roles mastery is preferable in that case), and stacking shields on shields with the disc priest will prevent having all of our heals wasted on overhealing (thus mastery being preferable to stronger heals, i.e. int, in that case as well). And on top of all that, it seems like Mastery also slightly pulls ahead of Int in 10m. Does that sound about right?
EDIT: and if I notice I'm lacking some spirit, would you recommend just swapping any/all of my 320 Mastery gems in my 3 prismatic sockets to Spirit on the fly as needed?