I don't have a mouse wheel, and my keyboard is very nonstandard. For these reasons, it's really important for me to be able to customize keys.
At first I thought there was no way for me to zoom in and out without a mouse wheel (it was not documented), but then I discovered an undocumented way to zoom in and out, using the '+' and '-' keys.
The problem here is that you cannot hold down those keys to zoom. Ok, sure. I'll tap '-' about 15-20 times at the beginning of each match--no problem. Actually no, the camera takes many liberties with the zoom level, and every time you die (which for me, is frequently), the camera is completely zoomed in again. Ok... I get an additional punishment of having to tap that key frantically each time I respawn.
Knowing I am in an extreme minority, here is my humble request:
1) Allow zooming in and out by holding down a hotkey (maximum time to zoom probably less than 1-2 seconds)
2) Do not reset the zoom level when I die. Pan the camera around all you like, but don't mess with my settings while I'm actually playing
3) Let me configure zoom in/zoom out keys of my own
4) Document all of your hot keys!!!