The food thing in Australia/NZ is stupidly easy to deal with. Check the "yes" box and then tell them what you actually have. The US form has specific types of foods listed so that is what they are looking for. The forms down under do not (and they are pretty clear about it in the signage and a video they showed just prior to arrival in AKL as well). Sorry you had to deal with it, but you did err on that one.

I was also given a secondary at SYD on my international-international connection a couple weeks ago and actually found it pleasantly entertaining how professional and polite they were. Two people are involved from their security crew, but they make it pretty clear that they are doing it that way to ensure that you receive good service and your rights aren't violated, not to intimidate. The A4 page with the description of your rights and options is also nice. I was ready to go for the wand/pat-down and they actually made me stop and rad the paper before they'd start.

Top notch all the way ^