[Antagonist]

What about a pure support type build?
Or maybe a pvp build?
What would these look like? end/spr? for max hp and healing capabilities during pvp and parties?

Yes, pure support builds use END and SPR (for tanking and SP). A PvP build would be pretty much the same as a PvM build, since you're pumping STR and/or END either way. If you prefer to be a battle type, you might want to avoid touching SPR, since you don't need it for the crit rate or the SP.

I'm not sure how well a pure support build can solo. Despite STR being your main stat upon each level-up, it's probably not sufficient to kill higher level mobs without the extra stat points pumped into it. I could be wrong though, since I haven't tried a build without STR.