What are the keeper rules going to be commish? Any 3 players on my roster at end of last year? If that's the case, it doesn't seem too fair as I would keep Cook, Chubb, and Kelce 😎 (and I'm ok with that btw lol).
I've normally seen keepers done based on the round the player was selected in the previous year draft to at least add a little strategy. In the case where you go by rounds and I get 3, I'd probably take (Cook in 1st, Chubb or Kelce in 2nd, and Lamb in 12th). In the live draft, I wouldn't have a 1st, 2nd, or 12th round pick. Just food for thought on how you set it up.
ETA:
A team can choose not to select any keepers from their previous year's team and they'd get a pick in every round based on their draft slot. If someone chooses 1 keeper player, they'd be slotted by appropriate round and have a pick in all other rounds, and so on/so forth up to the max keeper amount.
Normally players that are dropped during the season lose keeper status for the next year, even if they are added by another team (such as Chubb in my case when he got hurt, somebody dropped him and I picked him up off waivers). This is where FA slots play a role in managing your roster/bench space. If players are traded, it has been my experience they don't lose Keeper status (in a legit honest league), but I've seen where they do to prevent a-holes from trying to collude and stack a team and then split winnings in money leagues.
Last year's draft results/final roster by team