Hi Matty,
Yes - you can launch fr Whyte and head through boat passage by carefully following the beacons that will lead you out into Moreton Bay. Do be cautious as it can get very shallow. Your boat should draw minimal draft, but ensure that you follow each beacon particularly at low tide. For me id rather go via the river - its not that much further. i usually wet a line on the way there as there are plenty of fish on the way. The boat should be ok on a good day, although keep in mind the bay can change pretty quickly and coming home is when most people get caught out.
All the best mate - and let us know how you go.
Cheers - Jerry