@LightBender the events schedule thing is tied to scheduling events in the site's chat room. Basically, the option to mods for creating chat events is: "[Description] on [date] at [time] (UTC) for [duration] minutes. (optional) and every [recurring] days after that until [optional end date]". Those chat events are what get advertised in the events schedule sidebar.

Yeah, other than what is specifically provided (such as the PotW contest), there is no ability for per-site customization by the site's mods or community. The skin, colors, and icon are all fixed by SE.