Yes, you can specify a secondary logo via your theme.
Within MyMalcolm go the FAQ Section and click "Add a FAQ" towards to the top right of the screen.
On Team or Enterprise plans you can invite additional Team members to your instance.
Malcolm! has an inbuilt versioning system and optional scheduled publishing and approval functionality.
Tags are a way of describing your content and allow an alternate way for your customers to browse FAQ's aside from search and categories.
Yes - you do this via Settings in MyMalcolm.
If you are a user on more than one instance you'll see a "My Instances" screen when you login to MyMalcolm.