How safe is the Helix WiFi / gateway when managed outside the network on Helix Fi website / app?

Good day. 

Regarding your first question, the remote access that you're seeing on your settings isn't the same as the remote access through Helix-FI. The Helix-FI remote access is managed by its own security infrastructure.

For all your accounts, we suggest that you use a different and complex password to enhance the security. As for the 2FA, we'll foward your suggestion to the appropriate department so that it can be analysed.