Sorry for asking about the obvious but I don't know why, I have a doubt : "regular season week 1 midweek" is the step when you must cut players from 60 to 53, right? Thanks.

You actually have until the first game sim to cut to 53, but the midweek is a good time to do it just to make sure you don't hit the game sim with more than 53 players, which will cause the AI to do the cuts for you.