Follicular unit extraction for keratosis pilaris

That's pretty much exactly what should happen. Your transplants will shed within the first month, and so naturally a lot will fall out with the scabs. They'll start to regrow over the next 6 months or so. If there's no blood or any signs of trauma its highly unlikely you're losing grafts.

This is not at all a usual complication. Go to your hair transplant surgeon if you haven't already and ask them about it, and follow whatever instructions they give you after. Without seeing you in person there's no way to make an accurate diagnosis.

Final results generally take about a year to achieve. Over the next few months you'll probably keep seeing new hairs sprouting, and then for the last few months before you are finished it will mostly be the sprouted hairs growing and maturing.