Hi Avocado,
Sorry for a delayed reply, your message got lost in a frenzy somewhere!

If your boyfriend has an alert against his name, it usualy means that when applying for anything in NZ again, you will be very thoroughly checked out. If it was litteraly a broken window (assuming its a criminal damage offence and there was no prison sentence etc?) then there shouldnt be any real problems, provided that this conviction is explicitly revealed on any applications. And be prepared for delayed processing times as immigration does the major once over on your past. If you were excluded from NZ, they would most certainly have said so.

Can't really advise you on the Aussie visas, so i'd recommend you take a visit to http://www.movetooz.org and post the question on the Australian visas on their forum.

All the best