No. This information only resides in the PHPrelay file you place on your FileMaker Server. It is not used in any DayBack database, cookie, or server.
Yes. But remember that some access rights may not be reflected in DayBack's interface. For example, if you have record level access privileges set so that a given privilege set can't see a record, then that record won't show up in DayBack. No problem.
But if FileMaker's record level access says that a given privilege set can only edit a record under certain circumstances, that record will appear editable to logged in users as DayBack can't evaluate the access rights until the user tries to edit it. So users will be able to, for example, drag an event to a new date: the drag just won't take and will be reverted after users see a dialog saying the action isn't permitted.
Definitely. More here: Only See My Events.
Yes. More here: read only.
Only admins can see Account Settings. If you're of of the administrators for a DayBack group you can decide which group members have Admin access.
No. =)