Last I've used the editor was last year and I remember you could modify terrain somewhat, add items on the maps, add monsters. I wonder what is actually possible? Have new options appeared over the year? Or was it all focused on the coding side of things?
For instance, how about building outer-world structures? Is that possible? Like some basic fort or a maze?
Any other fun options I haven't found last time/weren't present?
Would it be possible to easily create some sort of scavenger hunts for rewards? For instance bring someone each type of gem to get a reward or similar? Or does that go beyond the scope of "here you noob fill this quest template and you're good to go"?

Also, I remember last time I had some issue with a crash on the bridge due to a duergar presence or an item presence (don't remember exactly, been a while back). Are there some things you guys know shouldn't be done? I know for certain adding a skill to monsters to summon other monsters was notoriously crashing my game, but I've never discovered the cause of the other less predictable crash... Amount of loose items on the map? Amount of loose monsters? Too many monster types?