Which gear is better?

[Risvertasashi]

Am I incorrect in thinking that wearing i180 PvP gear essentially removes the i150 sync for you? Since you are synced to i150, and the 30 morale raises the i180 pieces up 30 ilevels, is this the best option? The tooltips are confusing in that I still don't know how this works or if PvP materia works in PvP zones or not.

No-- ilvl always syncs to 150. In Frontlines, materia never works at any ilvl. In most Den modes, materia never works at any ilvl.