Hi there,
I think you have your answer already, a small minority of people would be prejudiced but overall Australia is less conservative than the UK. We asked similar questions before going out for interviews in June, my hair is red and DH was two tone blond & black & like you we're old enough to know better. We both have tattoo's and piercings but nothing that can't be removed or hidden for interview.
Speaking to my Australian boss in the UK & friends in Perth the overall answer we got was it'll matter less than in the UK particularly as we won't be in 'customer facing' roles & we would be judged on our skills not appearence however my boss here did say that with two candidates equal in all other ways it might go against you. We both work in banking/financial services IT which it was said tend to be more conservative than most other areas though. I'm assuming you are planning on doing similar work in which case I really don't think you have a problem (as an aside I have just finished a contract at a court where my boss was a goth - very impressive in a gown!)
My view has always been I wouldn't want to work for someone so judgemental however with visa's and our whole dream resting on one interview DH did decide to go for a single hair colour (peroxide blond!) and cut it just a little bit, he got the job and so did I!
I say forget Brisbane and come to Perth with us - Earlswood is spot-on about Northbridge (though it wasn't really the place for a family dinner on our last night, our son is 5!) & take a look at
The Perth Goth Meetup Group (Perth) - Meetup.com I'm sure Brisbane is the same though, I'm just showing my prejudice!
Jules x