I'm definitely not a morning person, but the last two seasons I've forced myself in between 45 minutes to an hour before light.

I depends on where I am hunting. Sometimes its 30 minutes and sometimes it's an 1.5 hours.

Usually around 30 mins for me. Seems about right.

Depends on the stand. One of my stands I go into an hour before sun-up and I have the whole woods to myself for a while, another stand if I go in an hour before sun-up I am bumping deer left and right. For that stand I wait until it is just getting light and I get in with no problems. I've noticed over the years thatI don't see a lot of natural deer movement right at first light. They are moving in the dark and just after the sun comes up but nothing right at sun-up in my woods. I was always one of the "in at least an hour ahead" guys but with morning temps in the 20s the last 2 days I have been going in right at sun-up and I have been seeing a lot of deer between 7 and 9 so I don't think I'm hurting my chances.