I can see the temptation as a DM of getting everything all sorted out in advance, but from a player perspective, I have to say I don’t want to see most of that before playing even one game. Sure, any necessary guidelines on creating an appropriate character, and directions or contact info., obviously. The rest, though...a lot of it should only be covered if and when it actually comes up, in my view. Let people play together and see how it goes, then start fleshing out various details of how the game will go, and how you will DM. If no player violates your 20 second rule, why even introduce it? Just keep it in mind in case there is a problem. The same goes for almost all the rest. Let people play once without all of that material, and take it from there. A new game is a bunch of people getting together- they should all agree on how to behave, or work out compromises. The DM’s power starts when the game starts, I don’t think they should start by going into details like what happens when a session is missed! Maybe there won’t even be a second session, or a missed session. Don’t write a manual- deal with your group as it actually turns out to be, and settle on any group rules then, is my take on it.