Popinjay: Navagon, that is incredible, how long did it take to construct?
I wish I knew. I just keep adding to it. It was started around the begining of Feb so it's had a good few hours invested in it now. I've just added a canal complete with several tunnels and bridges that exits somewhere near my harbour building (added some more screenshots).
Gersen: Probably the usual "south-west" (or is it "south-east" ?) bug, even if lava, fire, water is completely sealed, it's still possible to get burned/drowned if you touch the south-east corner of said block. Also sometime you have the little "fire-spark" thingy who are able to jump through the south-west corner and ignite your stuff.
I had the issue very often in a "under-lava" room at the bottom of my main base... that's why I decided to uses stone-slab as floor for this room instead of wood :).
I've got a lot of wooden floors too. But they're contained within a stone border just to be safe. Hopefully that will be enough.