Hi Peter, in order to do that, you would have to do as I told you before:
Edit the email account permissions (by editing the account itself) and then take away the permissions from the email account creator.
As to the tutorials, you are right. The wiki is greatly outdated right now... It would be great if we had more help with it by Community users.. that is why it is a Wiki on the first place hah. In order to edit it, you would need to sign up, and simply edit it as any wiki document. You should find more info about this in there.
Regarding videos, we do have a YT account named fengoffice, but there barely are videos in there as we have not had the time yet to create and upload new ones.
Best regards,
Francisco