Unless the website has changed it at some point, the password creation rules will be easily accessible just by going to the account creation page. Having it copied to the login page is not going to help people guess your password in any meaningful way.
Not necessarily. Nebula operates at a far, far smaller scope, with an emphasis on quality of videos over quantity, and every user is a paid user. If every user of YouTube was paying a couple bucks per month, they’d be making in the high tens of billions of dollars of revenue per year, several times more than they do with ads. Plus YouTube has a ridiculously huge amount of essentially worthless videos because literally anyone can upload a 10 hour video, so surely their hosting costs are higher per user than Nebula.