Thanks a mill @nancypants & @number_6 for your feedback. Sorry, I was a tad too quick on the post button so forgot to add the actual date of return (updated in the original post).
OK, so no need to stop over in Canberra by the sound of it (and general feedback based on the time constraint) the overall consensus is pointing towards flying rather than road "trippin'" based on what we had in mind.
The itinerary looks as follows (bold means booked and not changeable).
Nov 8th arriving Sydney a.m. hotel booked until 11th
Nov 11th SYD -> Uluru (AYQ)
Nov 13th AYQ -> SYD p.m
Nov 14th -> OPEN
Nov 18th -> Arrive MEL (or could be pushed to the 19th of Nov)
Nov 21 (after midnight to 22nd, flight out at 01:00 to HKG and back to Europe)
so this leaves us with 5 "open" days... Should we maybe fly off to BNE from SYD on the 13th already, stay a few days there and fly down to MEL (a tad earlier maybe) and rent a car when there and drive around in the MEL area instead?
@nancypants, seems like we need to stop by Albury and visit mom in law :-D