You should optimally be around 83 degrees C while driving. It will naturally go up a bit after your stopped for a while, so when your driving you seem fine.
It is a little warm when stopped, so it's probably time for a more affective fan setup.
I think it is worth checking the fan flow directions, as it sounds like you should indeed have a pretty effective cooling setup.
As for running water vs
antifreeze, running straight distilled water will run cooler than anti freeze.
Water is a more effective coolant than
antifreeze.
Antifreeze simply has a lower freezing point (and adds anti-corrosives).
I have been running Distilled water, Water Wetter and 15% antifreeze and my coolant temps never go over 84 degrees C while driving even in the hottest weather, and even when stopped in traffic for extended time, it never exceeds 88 degrees C.