You will probably get a 24 hour cycle with around 1800ish max and 850ish minimum. The high water usually hits the top of Lodore canyon around noon. Unless you have an unusual trip, there is no need for a super early push off on day 1. The high water does not seem to hit the middle canyon until 2 to 4 in the afternoon and does not seem worth waiting for on day 2. Bugs never seem to be a big problem there. A few mosquitos at the put in and a few if you camp down below whirlpool canyon. the afternoon wind can be the biggest issue! particularly on your last day out, get an early start that day! Have Fun!