Flushing is a lot of the time personal preference as I know a lot of growers who dont flush. Personally I think anyone who doesn't flush, is a ding dong.. But that's just me... Flushing will have nothing to do with drying, what flushing does, is washed out all the salt build up within your plants and grow medium. This just ensures a tastier, smoother smoke.
Flushing has nothing to do with molding. Now when drying, you want it to be in a controlled environment such as what you grew it in.. If you don't have an adequate drying unit/area, then mold may be an issue (depending on the temps and humidity while drying)
Do yourself a favor, make a nice drying unit, the potency of your end result has a lot to do with how you dry and cure your buds.
Leaving it in the dark and not feeding makes the plant think its dying, thus speeds up production. It is a good tactic.
Ya theres many ways to skin a cat in this sense. Personal preference big time on this.
When i first started growing, I use to trim the entire branch/buds and dry, then cure.
But now, I only trim off the big fan leaves, and leave the rest on there while it drys. (Please make sure your drying in complete darkness) then when the stem cracks (5-7 days of drying) I do a more extensive final trim, then start the curing.
Hope this helps, and good luck!