R6900 - Why Use Genie to Remotely Manage My Router?

I'm trying to set up my router for remote management via the NO-IP DDNS service. I'm having no luck so far and getting error messages similar to others I've seen on this forum. Can anyone please give me direct pointers and help me understand a few things?

1. Do I need to use Genie for remote management or can I directly access the router through my DDNS (or IP number) and a port number?
2. If I use Genie, does Genie act as a VPN so the login password isn't sent via clear text? If not, why use Genie?
3. The router is being used in a condo rental unit so I'm not planning on leaving a computer at the condo. The instructions I've seen for setting up Genie for remote management say you need to load the app on a local computer and a remote computer. After I configure it this way, can I remove the local computer (at the condo) and still access the router via the remote computer?

Thanks so much guys!