Yes, the discord is open to everybody. The easiest way to get to it is to do /discord while ingame and a link will pop up :)
A number of new players have asked for this.
That would probably be ok, the ones that aren't really allowed are the x-ray mods and stuff like that.
We have coreprotect for locking doors, chests, furnaces, ect.... We don't have a land-claim plugin or anything, but if somebody griefs you, staff can find out who it was, ban them, and undo the damage. We've had extraordinarly few incidents of greif though.
Playerbase depends on what timezone you are, most of our players seem to be in North America, but we have a smattering of Europeans and a gang of Aussies.
It's a very friendly small survival server. We tend to be quite relaxed about most things, pvp is only consensual so we don't have drama or anything from that. Most people are happy to help each other out. We don't seem to use the forums too much, but we have a discord which is reasonably more active.