Lots of questions. Here's what I do.
I use the substrate method and just put the eggs right into the vermiculite. I usually set up 6 qt Sterilite tubs with 250 grams of vermiculite and put them in the incubator dry. I also put bottled water in the incubator so everything is at the incubation temp. When the eggs are laid, I mix 300 grams of the bottled water into the vermiculite and knead the substrate until it is very evenly mixed. I dig a slight depression where I will place the eggs and push some of the vermiculite up against the side of the eggs. Make sure the eggs aren't touching the side walls of the tub. I then cover the tub with Press n Seal and no lid. With the Press n Seal on it should maintain your humidity levels just fine. I will pull the PnS back about every 4 days just for air exchange. That's it. As far as the temps go, I have been running my incubator at lower temps this year. I have the T-stat set for 87.5 and watch so that my thermometers aren't showing temps above 89.
For cleaning my girls I just use Dawn dish soap but I imagine any simple dish soap will do providing there aren't other chemicals or scents in it. I just put a few drops in a tub of water and then wipe her down with a wash cloth or the likes and then wipe her down again with clean water in a fresh wet cloth. I make sure she has a fresh clean tub and if she is in a rack that has solid walls, I will move her to a new slot just to make certain she doesn't have the scent in with her. As far as feeding goes, you can give her a couple days to settle back and then try. At the temps I'm incubating at, the eggs probably wont hatch for about 60+ days. I just let them pip of their own. I never cut unless one egg hasn't pipped for 24 hours after all others.
This is just what I am doing. Others will say substrateless is better. Some incubate at 90 degrees. Some people just use lids on the tubs instead of PnS. Some others will cut their eggs. So there are many ways to skin the proverbial cat, but you should do what you are comfortable with. Best of luck