Probably, maybe, and maybe.
I've seen as small as 200 size (tri and quad classes are a bit like comparing . . . oranges and tangerines), so don't see why it couldn't shrink just a touch more . . . weight budget would be crazy slim, though.
If you never touch the servo, then probably . . . I've seen the tough tilt strip a metal gear servo on a moderate landing, though. There are some pretty strong, precise sub-micro servos . . . Gyroscopic forces are pretty stiff, but it should still have a chance . . .
Dunno about the 3D printed. It can make precise, but hard to say if you can build it in a way to keep the tilt from shattering on impact. Survivability of the tilt and servo in less-than-perfect landings is always the challenge on tri's . . . one thing they borrow from their Heli heritage that quads are more immune to. That being said, IIRC, the 200 class tri was 3D printed . . .