Greetings Gergoth!
I don't personally own a lvl 60 pally just yet , however I had the same dilemmas as you did in this thread.I wandered around SW getting a lot of answers from high level pallys and I also had a discussion on another thread with a more experienced player. And maybe the experience that I received from them might also benefit you

We will tackle the questions one by one :
1.Should I try AoE farm?
There are a couple of die hard pally tanks fans on nostalrius. They will strongly advise you to keep up the protection tree . However they all seem to be in the level 35-50 range , indicative of their slow leveling speed. Most of thos whom get high xp very quick play in a group. So RETRIBUTION is the answer if you don't have a few friends who can aid your dps.
2.2h or 1h and a shield?
2h weapons are slower. Hence they will proc a lot more than 1h and a shield.And since you want a 2h weapon, you know it: spec retribution and level quick on your own

3.Prot or Retri
You see where I am going here. Once again Retribution. Consider playing holy or prot as a pally if you have a group that can fill the dps you crave but can't dish out on yourself. Ergo the only option for solo questing is retribution. This seems to be the consensus in game and on the forums.
4.Leveling experience and dungeons vs. quests.
Alright now . Group plus prot and holy = fun and fast. prot or holy minus group=slow and a bit frustrating.
Retri is appearantly the only viable spec for solo leveling as a pally.
It should also be noted that dungeons GREATLY hinder your xp gain. So you are better of questing anyways.But some nice pieces of gear every one or two levels should come in handy.
P.S. I come across as being a bit rude costantly advocating retribution as the only spec on the face of the earth. I am sorry for that. Consider respec as higher levels i.e. 50-54 in holy tree so you can heal in raids , OR to tank in dungeons ( no raid prospects of tanking for pallies. Perhaps offtanking whelps in Ony . But meh..).