@ThomasLewis is correct, Flarum's core is more of a framework than a complete forum. It can function without any extensions, but it's seriously bare bones. Having "core" features in extensions, whether made by Flarum or someone else, means they can be turned off and replaced in no time at all.
A few of these are covered by existing extensions.
User List
Anti-Spam System
Check out Askimet, it's a Flarum extension that comes with every default install.
Private Messaging
Check out Flagrow Byobu
Warnig People
Check out the aforementioned User Management by Reflar
Moderation and Stats are two areas that are not well requested and there are currently no extensions I can think of off the top of my head that fulfill the need. I'd suggest making two separate requests in this tag for those features. Someone usually steps up when they see a need.
