Keying in on the weapon trap stuff, in that they seem to be doing alright. Material definitely makes a huge difference: Green glass discs couldn't do much to elks and such besides chopping off their feet* and basically nothing to goblins, while steel ones would occasionally rip something in half, even when the steel were considerably lower quality and the target was armored. Also, 10x traps have a pretty good chance of causing something that walks into it to dodge away. Nice bonus if you've got a decent drop right beside th'trap.
* Kinda' funny story with that, actually the first time I've come close to being truly horrified by the atrocities I was committing in this game: I had taken one of my hyperspeed fortresses and built a line of 10x green disc weapon traps across a good 3/4ths of the map, walling off the parts that weren't trapped. What would happen is wildlife, horses, elks, and muskox primarily, would wander in and get their hooves hacked off by by the traps. They would promptly fall to the ground and wander around for a while. This would happen to entire herds more or less simultaneously.
The imagery was just horrific, having a mental picture of six or seven animals, limbs chopped off at the ankle, crawling around on the plains, some of them slowly bleeding out from other wounds. Freaking out and fleeing as flash!dwarves ran up to pick up the removed hooves for craftwork. Probably a good couple hundred animals died to those traps, most of them after dragging themselves a pretty considerably distance from the initial trap that crippled 'em, trailing blood and detritus.
On the bright side, it is a mildly effective way to get craft material without having to deal with actually butchering and storing all the parts that comes from a full animal. Every horse that wanders out of the trap without dying is another 12 crafts.