Thank you for your message.
Bypassing a firewall doesn't mean that it's dangerous. Remote connection between RU Viewer and RU Host is always encrypted regardless of connection type used be it direct connection
or Internet-ID connection. Here is more information
about Remote Utilities security.
That said, Internet-ID connection
simply removes the hassle of opening a port in your firewall settings which would be necessary if you decided to use direct connection. It may even be considered more secure (in terms of open ports) than direct connection since it doesn't require opening a port and creating a firewall rule.
Let me know if you have other questions.