Just beware that they are untested. I think they should work, but who knows, right?
Yes.
Pogo pin adapter should NOT be 0.8mm, that will make it less sturdy.
If you’re using my design, then yes.
Not on oshpark. I could maybe set up things on seed or somewhere that would make that possible.
Of course, I could also just give you the design files, and you could order them assembled from lots of places.