Don't plan on working until you have the work visa. Just having family to stay with doesn't necessarily mean you're eligible for a work visa.
As for exams, Australia, like pretty much every country, only recognises licences that have been issued, and doesn't credit exams that were completed in preparation for a foreign licence. In fact, Oz does a better job (from a licence conversion candidate's perspective) than Europe or the USA: A single law exam to ensure you understand the rules, a flight review (or possibly a flight test. Can't remember) and some paperwork + money. Even type ratings are a 'rubber stamp' carry over. Compare that to converting to JAA/EASA or FAA.