No.
In order for people to register you must have port 80 (HTTP) open. If you don't, there is no other way for people to connect.
If you are scared of vulnerabilities, have someone experienced check the security of your scripts.
Btw, if you can't set your serverlist.txt, try copying this.
ServerName
ServerName (tab here) 29000:IP ADDRESS (tab here) 11
And save.
For WinSCP, use the DHCLIENT command to acquire an IP address through RedHat and then reserve this IP address in your router configuration.
After that, use the IP that RedHat gave you and insert username and password.
Done.