Wow, I was gone for a bit and missed a bunch!
ChicknBaron, hopefully I can answer these in the order you asked:
Oxygen is really important at hatch - they need a lot in order to hatch since it is hard work. Most times, when someone gets eggs to develop and go all the way to lockdown and then not have them hatch, it is because of lack of ventilation. So I would take the plugs out. If you think about it, there isn't a huge difference between 67% and 70% and 70% is only a rough guide anyway - it doesn't need to be exact, just "around 70%". Some people use straws to add water through the vent holes to avoid opening the incubator if the humidity starts to go down too much. I bought some clear flexible tubing at TSC and I can add water that way if necessary.
Eggs actually lose weight throughout incubation, due to evaporation. Ideally you want them to lose somewhere between 9.5% and 13% of their total weight over the course of the 21 days. Too low or too high humidity can result in chicks that grow too big to be able to turn in the shells and therefore cannot zip and hatch, or chicks that are very sticky. A good idea for beginning incubators is to get a small egg scale that weighs in .1 increments. Weigh each egg before putting it in the incubator, and record the weights. Weigh again at 7-days, 14-days and lockdown, to determine that they are "on target". This can be very helpful if you have a bad hatch as by looking at your figures you will be able to tell if your humidity was too high or too low throughout. I have a chart I can PM you that shows what your target weight loss is for each of those weighing days. A less precise method is to compare the air cells at those same points along the way, with an air cell chart.
Hmm....I'm trying to picture your set up. In mine the chicks don't actually have access to the pan of water supplying the humidity as it is on the bottom of the incubator, and above the water is a hardware cloth shelf covered in rubberized shelf liner and the eggs sit on that. I would be concerned about a pan of water sitting where they can get into it, as they don't have much coordination in the first few hours after hatch and could well flop into the water and not be able to get back out. If you don't have any pips, it might be a good idea to add some marbles to avoid that. One thing I do to increase humidity is use feminine pads (I use cloth but disposable would work just as well). Because they are designed to be absorbent, they hold more water than a regular cloth, so the increase in humidity lasts for longer.
You might see pips any time now. I usually see pips sometime on day 20. From hatch to fully fluffed takes quite a few hours but is dependent on the humidity level. The higher it is, the longer it takes them to dry out. I would not open the incubator to take any out, no matter how tempted to are, if there are pipped eggs in there. And keep in mind that sometimes the pip can be down under the egg where you really can't see it. Since chicks can go up to 3 days without eating or drinking, it is better to err on the side of caution and NOT open the incubator to retrieve hatched chicks, since you could be spelling the doom of an unhatched chick by doing so.
Hope I didn't miss any - let me know if I did.
The chickens/rooster were in the fence earlier and that went much better than I expected. Fern was out near the fence during all this and watching closely - but then she started getting overly excited and jumping on the fence - a little vibrating zap reminded her that is not acceptable behavior - so, she went off and pouted under the car.
