The more users, the bigger the chance a site will die.I'd argue that the more users a site has, the more important rules and moderation becomes. There is significantly less margin for error. Doesn't mean the site has to become stricter; means the people who run it should all be on pretty much the same page. Yes, very strict rules can send users away, however, a toxic community often proves to be even more detrimental to a site's reputation and thus its success.
Actually I would suggest a shorter ban for minor rule breaking. For example Not RPing in RP room, minor spam etc etc. I think 30mins-1hourish for minor bans, because that is the amount of time many people spend on here.