magic mouse zoom
Your zoom issue might be fixed by turning off ‘use scrolling gestures’ under Options. I have never used the magic mouse on my Mac – it is still in its packaging – but I know the zoom can be a problem on normal mice if the scrolling gestures are set.
Macs are lovely machines but unfortunately I think you will be disappointed by the performance of GW2. It just doesn’t work all that well on the Mac and you will most probably have crashing issues at big events. Most people seem to turn to Bootcamp and play the Win version.
You need to make sure you have right click set in your Macs settings.
As for the scrolling/zooming, as Figlilly points out there are a couple of settings in the Guild Wars Options panel. Have a look at the two Mac Beta settings, they both relate to mouse behaviour.
It’s worth noting that in order to right click with a magic mouse you need to ONLY have your finger on the right click spot. If you’ve still got your other finger resting in the normal left click spot it will count as a left click.