While I understand the annoyance of Crusader Aura not keeping your team synced in flight speed, I don't think it's a huge problem. I run a mixed ranged team with a Prot Pally lead and while the rest of the toons are indeed slower, you only need to do a quick stop every 26 seconds (I timed it) to avoid dropping follow. And this is while flying in a straight line. If you were to zigzag a bit, they would keep up ever longer. Alternatively, you could also just lead from another, slower toon while flying long distances.

Hunters have a major glyph that makes their Aspect of the Cheetah and Aspect of the Party increase their own mount speed by 10% as well, so they do keep up with pallies a bit better

If you want to do current content, other than in Looking For Raid, I would not recommend a melee team. Ranged generally seem to work better for PVE purposes due to the freedom of movement and positioning. Melee is in turn fantastic for PVP in my opinnion, as they don't get "shut down" quite as easy when people get on them. This is especially true with the super tanky DKs with CC breakers for days.

I suppose my recommendation would be not to compromise on your class choises, as atleast for me a lot of the enjoyment I get from the game is highly dependant on liking my team and toons (especially the usual lead). For example there was just something bugging me about my mixed team for ages. At that time I was leading from a monk tank. Tried switching it to healing and leading from a prot pally and instantly started enjoying the team a lot more, even if there was no real noticeable difference in overall performance.