The team is now level 68. I set them up so I can run the four alts with the paladin as the party leader and tank, and the priest as healer. For a short time I had the priest spec'ed Shadow and the paladin Holy. This got them through questing in Nagrand and three trips through Sethekk Halls. I fiddled with attack and heal macros and still have some work to do on those, but after a shaky first run, the other two runs were much smoother. For outdoors questing, very basic macros should do the job, at least once the paladin's weapons skills catch up!
None of the trips through Sethekk Halls were spotless. I was never able to get the group to avoid the final boss's AE more than once in any fight, and before long they were all dead. The hunter and pet survived just fine and thus Talon King Ikiss died every time and dished out some loot. While this zone has only two bosses and a heck of a lot of trash mobs to clear (with annoying abilities such as mind control, AE fear, and spell reflect auras) the final boss is the only boss in a sub-70 zone that has an extended loot table with some of the "tier zero" set pieces for the Burning Crusade expansion. The warlock and priest walked out with their set leggings, and the paladin got a DPS ring and belt (which also dropped on the second trip, sigh).
Anyway, the three trips through the zone left them between 10 and 15% of the way to level 68. The priest was pretty far ahead on experience, with the paladin several percentage points behind and the mage and warlock bringing up the rear. So I decided to try and even them out as much as I could, first by completing quests for all but the priest, and then grinding up experience while dropping group members as they reached parity with the priest. Eventually, they got to where the spread is 165 experience points. This means that they'll keep pace with each other and when one of them hits a new level, they all do.
I headed to Borean Tundra in Northrend and had them set their hearth at the inn. With the mage in the group I can port back to Shattrath or any of the horde cities whenever I need to. This morning I logged them in and grabbed some quests, completing one (kill 15 of the nerubian mobs around Warsong Hold). It was pretty easy going, but the paladin's relatively low weapon skills are a bit of a problem. I may head back to Outland and seek out quests in Shadowmoon Valley or Netherstorm while I get his weapon skills up to snuff. As an added incentive, he would be able to skin mobs there and complete the last few points he needs in order to reach 350 leatherworking, at which point he can learn Northrend recipes and work on those.
I figure that at 70 I will get them their starter flying skill and mounts, and not worry about the epic flying skill until level 77. Since they won't be using flying mounts in Northrend until then, and will only need them for a few of the Outland dungeons, there's no particular rush to purchase them, and I'm still building up the necessary gold and won't have enough when they hit 70 (the bank just hit the 11,000 gold mark this weekend). By the time the group hits 77, I should have more than enough gold to purchase all of the flying skills that are available.
In any case, they're just two levels from having a whole lot of options available to them. While Outland zones and dungeons won't provide the same experience amounts as Northrend will, they would be able to hit 71 and possibly 72 just running the normal level 70 Outland dungeons (and the heroic dungeons) a few times. I want to be able to run each of the Northrend instances more than once, and I want to complete the outdoors quests, and all of that should have me at 80 before I'm close to being done. Then again, the content is designed to lead you to 80, where you will spend your time farming faction, running heroics, and running raids/arenas if you are so inclined. Neither of the latter are among my goals. I do want to run all of the Northrend 5-man content, and then turn and see about running old-world content just for kicks. But that is, as ever, a good ways off.