For the first two questions....
The best thing to do is to collect the eggs as they are laid, and store them in a cool (not refrigerator cold, but cool) place. You can store them a week or 10 days and still get decent hatch rates, but the rates will fall after a couple weeks.
Set the eggs all at the same time in the bator. Don't put them in as they are laid, or you'll have a staggered hatch. By collecting them for a period of days and then setting all at once you avoid that problem. Since you stop turning and raise humidity at day 19, it is hard to do that if you have eggs all set a different times unless you have another incubator to just use as a hatcher. Even then, you wouldn't want to have eggs hitting day 19 more than maybe one group per week to allow time for hatching, removing the babies and cleaning up before the next batch needed to be moved from the incubator over to the hatcher.
Finally, open the bator as little as absolutely possible, especially during days 19-21 when the humiidty is higher. If turning by hand days 1-19, then open the bator just long enough to turn the eggs, and then close it right back up again.
Hope this helps
