1) I cut a sponge in half, dipped that is warm water and added it.. That was all the moisture I chose to do and I only did it the one time. my theory was that the hatching chicks would keep the humidity where it needed to be for the remaining hatchlings ... where I live our humidity is + - 50%
2) I never kept track of humidity within the incubator, instead I kept track of the air cells, measuring their development at 10/14 and 18 days.
3) I have a still air so my temps ran between 101-102.. I had a couple spikes of 103 and once it got down to 100 but it wasn't for more than a few hours and not more than a couple times. all chicks were hatched and in the brooder on the morning of the 21st day
4) as stated above my Hova Bator is still air and although I have an egg turner, I chose not to use it, I didn't feel it was running right when I ran my incubator empty for 24 hours.
Of course, as with anything, please understand what works best for me in my climate may not work for everyone. I followed the instructions for my incubator with my very first hatch last year and got great results, but the next 4 hatches were horrible with one hatch resulting in 1 chick that survived.. I had gotten ahold of some turkey eggs and after losing the first batch for what I believed was to much humidity I chose to run the second batch dry...The only difference between that batch and this one was that I had a borrowed forced air... after 4 months I decided I wanted to try it the same way with my still air and see if I got the same results, which I actually got better results this time.. I want to try once more while the weather is warm enough outside (to keep ambient room temps up) so I don't have to run a space heater in the incubator room.
I know some folks freak out about the humidity in the incubator, but a wise person told me with the turkey eggs that it didn't matter, the air cell and weight loss is what mattered and she was dead on target, when I quit flipping out over humidity I got better results.
Hope that helps