I don't believe the 8300 will do 3mm margins, that is only available on the 6xxx models. I don't think you can do borderless on sheet feed just roll paper. The 8300 is not as versatile in handling sheet feed. You may want to look at the Canon Wiki. They have a lot of information on the Canon printers and the driver setups.
http://canonipf.wikispaces.comMike