It depends .. if I have a top that has lots of seams on the perimeter and I am attaching a border .. yep I do stay stitch. Same goes for wone the entire top is finished I stay stitch around the perimeter. Once in a while a block may have seams that I want to make sure are all laying a certain way , I will stay stitch around the block , or if I am putting big sections together, sometimes the weight will pull the seams before they go through the machine.
I will do some bias edges with my walking foot to help keep them from stretching .
Stay stitching can save lots of aggrivation down the road.... and it takes so little time.

Only when necessary.

never have.....but never thought I needed to, either.

I do for bias edges, the perimeter of my quilt before binding, and any other time that I think it may be a good idea :D:D:D

only if I have too

I was taught to stay stitch for fabrics that ravel easily, curves and biases. I often do. In many cases, however, spray sizing, pressing and gentle handling will take care of the matter.

NO ! Of course I don't pin either..lol..unless I absolutely have to stick one in for a seam or something!!

I have stay stitched after quilting but before trimming batting & backing. I find it easier to add the binding.

Yep, why do it if you don't need too? If I'm not going to finished the quilt top is about the only time.