The tower I started is finally complete. Stage 1, 2 and 3 are finished and stage 4 has been postponed for a while in favour of doing other things. I also dug a massive tunnel, going well beyond the maximum viewdistance. Next I am going to dig another tunnel, but now under the main settlement. This should give me enough time(and stone) to think of another building project.
My only problem thusfar with multiplayer is that it can be laggy, so I hope performance gets patched before features.