I am still very new to this as well. Although new, I still see a lot of benefits for the babies to be incubated naturally. I would say that if they are all good, then you should not need to candle them again. They should be able to incubate and hatch perfectly fine. My ducks go off of their eggs for about 2-3 hours in the morning and about an hour at night and their eggs are developing perfectly (I have about a 90% of my eggs laid developing on time). All of the times I candle mine and they look like they are developing, I would say 49 out of 50 times, they hatch perfectly fine. After my first mistake of leaving the eggs in there and then them exploding all over the mother and other eggs, I have decided that is a mistake I never want to make again. Some people say that it is not necessary, but I beg to differ.
Some good advice is, some hens will push out the rotten eggs themselves and some will not. I have one turkey that will take the rotten eggs far away (she will peck the egg shell (not the membrane) and carry it away from her nest and just leave it there (not eat it) and another will literally just push it out of the nest and not carry it off. My other hen will sit on it, determined for it to hatch, and will let it rot and explode (she even gets worried if I take the rotten eggs away).
Here is some first hand experience that I hope you never have to go through.

If you go too long to candle correctly (I tried to candle at 21 days when the turkeys hatched at 28 days- I just learned to candle eggs right after I had exploding eggs) and are not sure if the eggs are good and it is around the time to hatch, smell them. It sounds like bad information, but you will not be able to accurately tell that the eggs are developed or if the rot is not letting light shine through correctly. Your nose will be able to tell you what eggs are rotting and what eggs are still good. When I smell mine, I take a good hard wiff (I want to be extra sure there isn't a baby in it) and about gag each time, but that one smell beats having to move the entire nest, try to clean up the area with the rotten egg (when it breaks) all the while having to smell it constantly baking in the sun. Not a pleasant experience. Not one at all.