I made a regular order not long ago (on the clearnet, nothing illegal) and this was on the packaging when I received it:
http://i.imgur.com/DGoNGjJ.jpg
I think it's worth the extra couple of bucks to buy domestically. Nothing new here, just a reminder.
Yep always go domestic in Australia (fucking islands). I've had clothes and other general internet orders get opened by customs as well.
The only thing I would be willing to try to get through is a couple of tabs of LSD in an envelope, because an Xray should just show that up as pieces of paper.