Incubating first time and need help

I have been spending hours searching through posts and can't seem to find what I need, so I decided to start a new thread. This is my first time incubating and really, I'm new to raising chickens (within the last 2 years). My husband has had chickens for years but he's lost on the topic too. Humidity. He got me for christmas a "FarmInnovators" incubator from Tractor Supply. It has auto turner, thermostat, humidity detector, digital countdown. Here's my issue as I see SO MANY different opinions. WE have had problems from day 1 with the humidity. The book it came with says to keep the humidity at 50-60% and when day 18 comes, open the caps off for more air, and raise the humidity to 60-70%.
We cannot keep the humidity steady. It's all over the place. We can start will the bottom tracks partially full of warm distilled water, and after about 8-10 hours, the humidity starts to drop. It's gone as low as 48%. We will add some water or maybe warm sponge, and then it goes up to the 70's! And the sponge is may 3X4 inch not saturated.
First off:
During the beginning, before candling at day 7 to check the air sacs, what does the humidity need to be?
After candling I'm assuming we go from there but still not sure of what it should be. Do I need to adjust as I go each candling session?
Secondly:
Day 18 and we take the eggs out of the turner and put them on the wire to hatch and within 4 hours they start hatching. It took 2 days for a total of 17 to hatch. My friend told me the temp was too high, but I never changed it -when the peeps started hatching we were at 68-70% humidity, temp never changes from 99.5 - 100.5 at most, usually 100. So was it too high??
All was going well, they were hatching and drying, and I was told to keep the incubator on lockdown. Well, the more chick that hatched the higher the humidity got (of course, respirations expel humidity)*I'm a nurse
So do I leave them in, take them out like 6 at a time, what do I do? I did find 2 that pipped and were alive but I think their eggs got rolled around from so many chicks kicking over them, that it looks like the holes were covered over by a shiny sticky film.
Thirdly:
We had about 7 that fully formed, didn't pip and died. I think it was because the humidity was so high. I feel so bad!

Any opinions and help i can get is appreciated.!! I tried to attach a picture of the incubator and eggs in the turner and out of the turner. but I can't find the place to do it. Any one ever use this kind? It was like $130 so it's not supposed to be a cheap one.
Thanks
Lynda

 

The eggs were a mix. I have top hats but most of them were Rhode Island reds, Black sex links, barred rocks and wyandots. Barnyard mix lol. The roosters are americana, a silkie/auracana mix and a brahma/Wyandot mix. First and third are huge, middle rooster a medium size.
And thank you so much for your input!!
The ones that didn't hatch were fully formed but very wet inside when I opened them so I assume they were drowned.