Hi All!

Looking for some help with a few questions. With the help of some friends and the people of this forum I've got healthy eggs in the incubator but now I've got a few additional questions. I've got 5 currently healthy eggs incubating. All candled with nice veins. I'm using press and seal in a tub with no air holes. Temps and humidity are remaining perfect within the tub. I'm "burping" them every few days to circulate some new air and plan to do it daily once I hit somewhere around day 50. So here are my questions:

1) How long can I continue to candle the eggs?
2) How long is it ok to have the tub out of the incubator for?
3) Should I start daily burping sooner than I mentioned above?
4) Anything else I should know?

Thanks!