*facepalm* I totally missed that you can make metal mechanisms. Your first objection to wooden ones applies 10x more to stone though. Lets see you make a practical stone latch. Meenwhile I'll be over here making one in a few minutes with a pocket knife and a few sticks. Also wood works fine for gears. Hell that's what most water wheels and windmills were made with IRL 
Dwarves have metal tools, rock is stronger than wood and lacks a grain you have to worry about, and there's no cultural issues about dwarves and stone. The opposite, in fact.
And dwarves
do make waterwheels and windmills out of wood.
How can a goblin steal a baby from its mother without the mother noticing over and over again? You'd think they'd learn to pay more attention to their kids, considering how much they complain once they notice...
Dwarves believe strongly in independence. A baby disappearing is a sign of independence, and a source of pride. It's the theft of the baby from the fortress, very nearly resembling death, from their perspective, that so bothers the dwarves.
Why does burning coal in an iron bin create an eternal flame?
It doesn't, it never did. Burning
lignite did, because it would never melt, but I hear that issue got fixed.
Why can't I think of a good question? Oh, yeah, I answer all of them before hitting Post.