Trimming isn't hard at all. Cut all big and small leaves off of the buds, careful not to snip the actual buds. I highly suggest you wear
some latex gloves, as the resin gets VERY sticky and hard to get off of
your hands. Trim all tiny bud leaves if you want, also, it makes for better
bag appeal when you have pure buds, and not buds with tiny leaves
on them.
It will take you longer than you expect to trim....at least it
was the case with me.
I have never had any experience with the last two days of darkness, but
it won't hurt to experiment.
For flushing, many recommend using clearex, although I never
experimented with it.
The only flush I have experience with is just plain ole ph'd water which
is just flushing the plants with 2X their container size in water.
(So 5 gallon pots would be flushed with 10 gallons of water)
Good luck on however you decide to flush and don't forget to come
back with wet weight, dry weight, and the big thing everyone waits for,
BUD porn and smoke reports!!!