Matrix33:
1. We can't shorten it. The game won't allow more than two upgrade paths for one unit, so we had to add the additional scout tier in order to fit in the missile units, since the militia/footman tier was already advancing into two seperate units. Obviously we're not going to remove a whole tier, since that'd give you access to top-notch missile units in no time at all. One thing we want to do, though, is make it possible to hire scouts at taverns. This way you won't have to train all your missile troops up from peasants, which, I understand, is very exasperating indeed. We'll do this as soon as we have the time and figure out how.
2. The heavy infantry is simply the normal infantry unit that has been standardised with two-handed weapons. They may swing slowly, but they move faster than shield-encumbered units, they have longer attack range and they deal out huge amounts of damage, so anyone charging into the midst of fifteen swinging greatswords is in a lot of trouble. If you don't like them, you can always use something else. But just in case, I'll give them a performance test.
3. Glad you like that. It may not be historical, but neither is lance-armed knights stopping in the middle of an infantry mob and poking people, so I figured we might as well separate them. The lancers aren't actually all that bad, either: massed couched lance charges sometimes cause huge casualties and even if a few of them blow it, their friends can cover for them.
Worbah:
There's no room on the army trees, but maybe we could add an alternative upgrade somewhere along the mercenary path. These berserker-type units seem to be in vogue, I'll talk to Lost-Lamb about whether we want to add them.