I don't know everything, but I've both talked to devs and run experiments over the years. Here is what I know and think.
I am 90% certain the look back period is 4 years. It may be longer, but it's definitely not shorter.
There is either no cost to lower divisions or minimal. Based on how this game is built in other parts we understand, my guess is a win is a win, regardless of level.
The elites pay attention to total wins, CCs, and NCs over the look back period. They may also look at final ranking, but I'm less confident.
There is a slight bump in importance for recent season. I do not know if there's any other multipliers. My guess would be either no, or it's linear.
I ran an experiment in Yost. I started 36-0 with 2 NCs in d3. I followed it up with 1 d2 season and 2 d1aa seasons. None of those 3 were impressive. Mostly quarterfinals.
At 5 years played in Yost, I stopped playing to see if my 5 year resume was good with to get an elite. I went 1/6 on apps and eventually landed at Nebraska with only 2 d1aa seasons and a d3 in my last 4.