Walls and Ceilings - lath/plaster to drywall

I've spent the weekend removing some walls in my 1928 house. They are lath and plaster. The question I have is how will I transition from drywall to plaster? For instance, I took out a wall, so now i have about an 8" gap along another wall where that wall once intersected. Also, how do I deal with corners where they put that metal screen mesh? I hate to remove the plaster from walls that dont' need to be messed with, so shoudl I just cut out the mesh as best I can and let hte drywaller butt his sheetrock up into the corner? Or shoudl I go ahead and complete remove the mesh, and allow the drywaller to mud over the small portion of plaster wall that will be affected? Also, Where I'm framing a new wall to line up with an existing plsater wall, shoudl I just hold back 1/2" from the face of the plaster to allow for sheetrock, or will I need to hold back more to account for the thickness of the mud? I'm planning on doing a skim coat over the entire space to try and create a nice smooth finish.

I try to end the lath & plaster in a nice straight line if possible. A carbide bit in a reciprocating saw can make a relatively straight cut through the lath & plaster. Then I take a scrap of sheet rock and hold it against the studs and compare it's thickness to the lath & plaster. Usually the plaster is thicker than the sheet rock, so I attach strips of old masonite, paneling or thin strips of wood to the studs. Then put your sheet rock up on the wall, hopefully you spaced it out pretty well (concentrate on the joint area). Then use ordinary drywall mud to feather the new sheet rock to the old lath & plaster.