Isn't the lack of an API problem actually getting worse right now, too? Since Dinnerbone left BUKKIT to go work for Mojang directly, hasn't the BUKKIT add-on system basically crashed and burned, meaning anyone that was developing for that architecture had to switch over to Forge or just stop development of their addons altogether?
I wouldn't know, I haven't run a dedicated server or used bukkit since the halforums server closed. I've been using FORGE at home and just playing LAN with the little woman, and even then only a couple hours a week.
I think it'll be easier if it is on a Mojang server for trying to help against a vanilla grief-fest. Or for addons at the very least. I wouldn't even mind making it a PvP type of thing.
What on god's green earth ever gave you that hilarious notion? If anything it'll make it worse, because mojang can't pay attention to a bajillion little shared server instances. There'd still be no API for modding/addons, as well.
Really, until they finish their mod API, hosting/maintaining a current, stable, customized , public minecraft server is pretty much a full time job in and of itself. The only ones who manage to do it... well, it IS their day job, pretty much, and often they ARE the authors of their own mods, like the MineZ guys.
And playing on them is still a shitty lagfest largely populated by jerkasses. Believe me, I've tried a few.