Hello everyone, looking to get a Ball Python in a month or two. I'd like to make sure the cage is set up as accurately as possible first. I have the following supplies that my cousin gave me. A 20 gallon long tank, heat lamp with 40 and 100 watt ZooMed Sunlight blue Daylight bulbs, and a 20-30 gallon UTH (which I plan on replacing) with a lamp-dimmer. Just a few questions and concerns;

-The room I plan on keeping my BP in is always at 70F, I've heard they need a warm side of 85F-90F, but is a cool side of 70F too low? How would I raise the cool side? I live in MI, so it get's cold during the winter!
-Should I provide a day/night cycle for my BP? I already have the heat lamp and daylight bulbs, I could use the 40w to keep the heat emitted down to a minimum.
-How important is the humidity? Should it be something that I constantly monitor?
-How many hides do I need? Just one of the warm side and one on the cool side?

Any other information or links to anything I could read would be really helpful. I mainly was just worried at the above though, and couldn't find exact answers.