I installed Fedora Server 25 a week or so ago on a small server, sshd was open (with an extremely strong random password) and fully functional at install time. SELinux has caused no issues, I actually chose to install docker in the installer at install-time and it came pre-configured to play nice with SELinux.
Firewalld on the other hand, I'm still figuring out (firewall-cmd is useful, but trying to translate iptables rules -> firewalld is proving harder than I expected)