-snip-
It has since been determined (I THINK, I don't know if there's proof or not but there's some hard evidence) that engravers need to have a certain skill level before they start engraving anything historical. Otherwise you'll just get circles. Good news, though, is that smoothing stone levels the skill. (I don't know if engraving minecart track levels the skill too, but you can smooth the track out afterwards to repeatedly gain skill points that way.)
As for my exploits... Sadly I haven't done anything too horrible. Atom-smashing pets, locking dwarves outside because of a 50-dude wave coming before I'm prepared, etc. Probably the worst thing I've done so far is currently ongoing. I have an evil fort, with a syndrome cloud. That's it--no zombies, no reanimation, nothing of extreme FUN yet. I don't know what the cloud does, because world.dat or whatever that file is, happens to be half a gig in size and I can't open it for reading in anything. Not even the text splitter I downloaded.
Anyway, my intention was locking the giga-wave outside to study them. No conclusive data, I still couldn't get anybody to really show any symptoms. (It didn't help that I had 5 or so aggressive kobold squads cutting them to pieces, though.) So when the next wave came in, I finally had my airlock operational, and noticed that the animals were covered in pus. Finally, I thought to myself, someone showing symptoms!
So I had them pastured in the airlock and am keeping them sealed up there to be studied.