I have a similar team makeup. paly, priest, 3xmages.

My paladin spec is almost exact to what you linked with the exception of Vindiction

Just for reference, ALL bosses in outland are immune to that debuff. That reason alone makes it a waste in my opinion.

you were right the first time about one hand spec. It ONLY increases the damage you do with a 1 handed weapon.... period. Since your paly will be tanking, most of your threat will come from holy dmg and not your weapon dmg... again a wasted spec, but I still but 3-4 in it just as a filler. (I didn't take spell warding).

For most fights you will be using retribution aura. The bonus effect from devotion is minimal at 70 and does not scale. Having retribution aura will greatly increase your threat generation on multiple mobs.

Again you are right on about pursuit. For mulitboxing that is just not feasible. Avoid all movement increases unless all your alts have them too