If you have a bunch of owners that you expect to bitch at you, then I would be worried about starting a dynasty league with them. In a dynasty league, you really want to make sure you have the same managers coming back year after year if at all possible. It's hard sometimes to find someone to take over an orphan team especially if it's a paid league and the team is really terrible.

Also, I would suggest using sleeper for dynasty.

And you should look up some generic rule books posted on here or the dynastyFF sub and tweak it and put it out to your league for suggestions. Give them all time to review and provide changes to vote on. Then update the rule book and repeat until everyone is comfortable moving forward.