Fusion is a managed 3rd party repo, isn’t it? AUR and copr is more individuals creating packages

I made the same move a few years back and really like it. Can’t say much regarding SELinux and security though. Regarding the AUR, it depends on how much you use it but I only rarely miss it. A lot of stuff that is not in the default fedora repos can be found in copr https://copr.fedorainfracloud.org/