Yes I will want to pay out more line after launch. I typically do a 100' long line launch, then let another few hundred feet out. Letting additional line out in a controlled manner is a difficult process when there's lots of pull and flying directly on the winder. I guess I could just let it go much faster, so it can't pull as hard, and see what happens.
I would remove the figure eight before reeling in. And probably walk it down 100ft at a time. Carabiner on the line, walk 100ft, secure at that point, walk back to anchor, reel in the 100ft, repeat. I like the idea of a "Henry's handle" (cleat on a board) for securing the line. I would not want to hold it by hand the whole time.
I have a large dog screw which is good for at least 200lb in good soil.