I'd like to remove the drywall from the two exterior walls of my corner
bedroom, add a couple of electrical outlets while they're exposed, and
put 3" fiberglass insulation batts between the studs. This house was
built in West Texas in 1959, so it has NO wall insulation at this time.
I don't want to use the blow-in or spray-in insulation. Several of
the drywall nails have "popped" over the years, which is another reason
to replace the existing drywall. The ceiling is insulated and the
drywall overhead is OK, so I don't plan on messing with it.

If anyone has any tips for making the joint between the new wall
drywall sheets and the existing ceiling drywall look good, please share
them with me. I'm somewhat familiar with drywall taping since I put it
in a large workshop I built a few years ago, but it was all NEW
drywall.

Would it be beneficial to make an incision about 1/16" deep about 2"
from the joint all along the ceiling sheets, and scrape out the old
paper tape and joint compound from those sheets? This would provide a
shallow channel to bed the new tape and it seems it would be easier to
smooth out the compound.

I've always used the conventional paper tape; would the fiberglass mesh
joint tape be better for this project?