Unless I am mistaken, there is now a slightly easier way of disabling the Firewall:

[1] Edit Group Settings → Shields → Firewall (Uncheck)
[2] Edit Group Settings → Status Bar → Firewall (Uncheck)

Unchecking those TWO settings will:
[1] Disable the Firewall
[2] Prevent the Status Bar issuing a Warning.

Is this a NEW option? I don’t recall seeing it before, so make sure you have the latest version of the workstation client installed.

HTH
Stephen