Shields don't appear to have a size, though I don't see why smaller copper shields would be of any particular benefit, unless there's some kind of odd sweet spot for shield bashing where the density still matters but the weight doesn't. Anyway, my Gremlin got to where she was consistently making Exceptional and Masterwork armor, so I had her make a full suit of Adamantine for herself. Proper training is on hold while I slowly haul thousands of logs to my stockpiles, since I finally got fed up and clearcut most of the surface trees. One woodcutter managed to get badly mauled by a Giant Alligator that fell out of a felled tree, and there were plenty of injuries from falling logs, but surprisingly nothing crippling or lethal.
Incidentally, at one point the gremlin decided to spend some time helping with the hauling. Normally this is fine, but well, the task she took upon herself was to drag the recent corpse of a forgotten beast to one of the refuse stockpiles. It's made of Aventurine, and weighs 20547Γ. Bear in mind that gremlins weigh roughly 10Γ.
Efforts to capture and tame the great beasts of the world continue, with the hydra population reaching 60, and another forgotten beast successfully captured in a webbed cage trap. It's a huge sheep with external ribs, a fat bulging trunk, and poisonous vapors. Not sure what effect its vapors have yet, so it's staying in its cage for now; I'll figure out a use for it eventually. Hmm, it's a sheep... can forgotten beasts be sheared? Also, I now have a single cage with no fewer than 363 crundles packed into it. It weighs 4257Γ, so when I say I have tons of crundles, I am speaking the literal truth.
Sadly, the presence of the human Guild Representative in my fortress as a citizen bard apparently prevents negotiation of further trade agreements with the humans. As a result, I no longer have the ability to request specific goods from either caravan, as the dwarven Outpost Liaison moved in when the queen did.
I can't say I've ever had migrants or other visitors (aside from FBs, of course) arrive from the caverns, though cavern departures seem fairly common.