I trucked a 28Ft Giles Wanderer (cravel planked) from Brisbane to Perth back in early 90's. Half the critics said it would be matchwood by the time it got there and the other half said "no problems". The "no problem" crowd were right
It took about 7 days from memory and needed pumping once about 12 hours after re-launching.
It was quite a lot cheaper and much much quicker than sailing from Perth to Brisbane.
As for Whitsundays to Brisbane; well that is a very easy run for the experienced sailor but would be more difficult for a beginner. It really depends on what sort of beginner you really are.
It you have some history
of taking on new projects and following through on them, then you would probably be OK; however if this is your first step into a new undertaking, it will be more difficult.
Timing could be an issue, right now the wind
will be on the nose the whole trip and this is not so good for the beginner. You won't expect following winds until the wet season kicks in and you will want to get south before the cyclone season.
The plus point for sailing is that the easy stretches will be at the start (leaving the Whitsundays) and this will ease the learning
curve so that you will have gained some experience by the time you exit the protection of the Barrier Reef. Even then, it is not a tough trip to get to Brissy.
In my mind, the easiest
way is to use cash
and truck the boat; the best
way is to leave the boat up north until October, then send a few weeks sailing around the Whitsundays getting some experience and then take your time and slowly head
south around November. Take as long as you can.
I realize you may not have the time available for such a plan so an alternate plan is find a skipper who is willing to bash south against the trades and go with him right now.
Good luck with whatever you decide.