@David, I won't disagree that more missions would be nice, though that goes for most games.
@Wyvern, I can't say to much on classes since I've only tried archer/thief thus far. I like the combo because hide and shoot make a nice combination, and I can always duel wield a dagger in my other hand if I want melee damage, although even at close range shoot is pretty good.
As for multiclassing, from what I gather you can get both classes to l150, and then start earning faux levels which are like extra stat increases, until you can get to level 151 in both classes.
The one thing I haven't quite managed to work out is whether remorting is affectively restarting with no bonuses or not, but since it will take me a while to get to level 150 I'll worry about it then.
One thing I will say, is that it seems wise to have two classes at the same level, since you only earn practices and trains for your primary class, but don't have abilities for your primary class each level, so levelling both classes together means your in a better position fo arriving at abilities fairly consistently rather than getting a bunch of abilities and nothing to train them with, plus then your progression can be relatively (especially in hardcore).
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)