prunning Wisteria (Hygrophila difformis)?

Need to start prunning Wisteria (Hygrophila difformis).
Most of what I read is just chop it off and stick the top in the gravel.

There are 3 types of growth from the plant that I don't know how to deal
with and would like some advice;

Straight white roots(?) growing down to the gravel from the stem.
Leave them, or remove them?
Cut them or pinch them?

Black webs of roots(?) growing from the stem.
Leave them, or remove them?
Cut them or pinch them?

Horizontal Branches 7" long, can these be cut off to keep a more
vertical shape?
Can the branches be planted vertically?

When I chop off the top half of the plant, and plant the top, how can I
keep the bottom from branching?

Cutting off the top to replant the top, should I cut below or above an
existing leaf/white root/black web?

--
Jim Anderson
( 8(|) To email me just pull my_finger