When hanging blue board for veneer plaster, should the board overlap on outside corners like normal drywall or should they end on the edge of the studs and the corner will be filled in with veneer (and a corner edge piece)?
Corner bead is used on plaster work too, so run it the same way as you would drywall. My preference is to run one piece over the edge of the other side, but slightly behind. This can be achieved as well when the board is ran past the corner, then scored at the corner an broke back and finished cutting. Use a drywall rasp (cheese grater) to insure the break is back a little behind the corner if needed.
It doesn't matter. Some folks like to think that having wallboard behind then corner bead offers support. It doesn't. For one thing, it never completely fills the inside of the bead. No one is that precise. For another, it's wallboard, which is inherently soft. If the bead gets hit hard enough to deform it, gypsum or other wallboard material isn't going to help. The damage is done.
Most hangers cut flush to the framing. This eliminates the need for any rasp work, which wastes time.
I usually lap about half the width of the wallboard (along the lines of what Jack describes). It just makes me feel like I've done a more precise job of fitment. It doesn't matter, though.