So, it finally happened.
It's Spring 555, I'm carving out a new entrance to my fortress, and all of a sudden, a dragon appears, complete with legendary nickname. I sound the alarms to get everyone indoors, mobilize the militia, and watch in anticipation as he traverses the southern mountain, where my new entry is being built, hops down into my old pastureage area, walled off between the northern and southern mountains, and proceeds to torch every single one of my reindeers and dogs (I had them in pastures to control their whereabouts) until there's absolutely no hint that they even existed, setting off a blaze that rips through the densely wooded valley and probably would have reduced the entire map to ash had it not been for some timely rain.
Anyway, he enters my fort and is promptly caught in a trap that I had placed for Giant Kea. I set my best non-militia animal trainer to tame him, and he immediately became "well-tamed". I have a little nook of the fortress set aside for him, free of flammable plant life and blocked off with a one-tile entrance. My questions are as follows:
A. Is it safe to let him out of his cage? If I set him to a pasture adjacent to the training area, will he respect the pasture?
B. How many trainers can I expect to lose before he becomes a war dragon if he's only "well-trained" but not domesticated? How can I increase his training level?
C. My ultimate plan is to shack him up in a cave with my elite marksdwarf vampire, either on the ridge west of the map, or on the peak of the southern mountain, above the new entrance to the fortress. Will both dragon and vampire respect any burrows I place within this cave, or will I need to create some sort of a barrier that I would open in the event that their services were needed? What are the odds of one of them killing the other if they're left alone with nothing to do for an extended period of time? Say, if the vampire tantrums and tries fighting the dragon, and the dragon incinerates him? Also, do vampires ever feed on animals? And could one kill a dragon?
Anyway, that's my current situation. My ultimate goal is to keep both dragonfire and hungry vampires as far away as possible from my elite and absolutely deadly military. I'm also considering some strategic logging to make sure that the upper branches of trees in the valley don't connect. Possibly diverting the river into a series of bridged channels to prevent the spread of groundfire as well. In short, retooling the valley for dragon combat.