The Lord Packman has done something with something to expand the post text entry window and there's now a preview button you might have seen.
Projectiles, namely siege weapons, don't currently think very hard about the Z coordinate. That's kind of a mess in general, since objects flying through 3D space tend to move along parabolic paths, and those don't work to well along grids like the one in DF in the sense that it would be harder to predict what you are going to hit (it could sort of show you a flight path or something, but it wouldn't necessarily be pretty).
Adventurers losing their map memory is kind of a necessity, at least to some extent. It should keep their entity affiliations over time, but I think there were some issues with that so I might have put a lot of it aside for now (perhaps due to some civil war style problem, I don't recall). Ideally, later on they'll act roughly as you want them to act in your absence and also as an active historical figure in the world like everybody else.
Water hardens magma, and it doesn't take very much. This is because it doesn't track the magma's current temperature -- if it did that, it would just cool off and not work as people want it to work in terms of violent weaponry and so on. I might look at it more later on. Right now it's fairly simple of necessity, but you can cool it off with water contact.