To be honest normally it's 18+ but I've known a 32 year old that acted like a high school drama queen. Age is tough to call on in my opinion.
What I expect though? First if the player can't follow directions they're automatically red-flagged by me, because really there's a good chance they skimmed over the rules and won't follow said rules. They have to respect all the mods (if there are multiple running the game) because I don't believe in the favorite thing. I also expect players to be able to spell and spellcheck and not make excuses for not having a spellcheck or not knowing how to work it.
Lastly, expecting a player to act with respect and maturity if you make a decision based on a request from them. I can't stand when muns pull the hissy fit and talk to other players because they didn't get their way. And when they leave because they couldn't fill their fangirl/boy wishes. Though that could tie into the rule/directions thing as well. I expect them to take the decision in stride and just get over it if they don't get their way; obviously there's a reason we did or didn't allow the request.
And the only times I think posting deadlines were lowered was with the move over to IJ, and December.