3) Tags are not subreddits. A post can be a part of three different tags, while subreddits are exclusive (but prone to duplication/crossposting - crossposting is not a thing on Hubski). Further, tags have no moderators. Further, nothing has moderators.
This is... you know, I could get used to this!
Hubski's certainly not what I'm used to, but it's very... refreshing. And I quite like that! Thank you for the tips and warm welcome!