I can answer number 3 (and 4):
1) get Finn's editor
2) DL all the historic teams - they are invidual zip files (do not unzip each team file) - see my sig for link to files
3) open Finn's editor and read in a default roster file (not a modded one)
4) select to import team by right clicking on team name in editor
5) select the same historic franchise to import for the team you show in the editor (ie: 89 49ers for the 49ers, 85 Bears for the Bears, etc...)
6) simply go to each team in the roster and repeat #5
7) save your file with a new roster name
Note: the depth charts do get whacked out a bit in this process. Check those when you get in the game for each teams before starting a franchise.
Also, there is no way currently to rename regular teams to historic teams, so you will see Chicago Bears instead of '85 Chicago Bears.
Good luck!