I have decided to go ahead and buil my own incubator but i still had a few questions.

1.How do i know if my fan(s) are providing enough circulation.
2.How do i make sure my humidity stays consistent threw the entire fridge.
3.How much heat tape is required? I have seen some with 1 11" strip and some with 2.
4.How often should i open the fridge?How much is too much?
5.I plan on using the Hatchrite medium and heard i would need to add water to it even though it says otherwise on the bag.Is this true;If so how much do i add?
6.If i were to have 2 incubators set up with a clutch in each would one being set at 88 and one at 89 change anything (ex.sex ratio)?
Thank You