I have added zooming function which is bind to Right Mouse Button. So i suggest to change alt-fire binding, to something else like Middle Mouse Button.
I have also corrected some offsets, so camera now should be little more back and lower. Just remember to set up proer FOV to your monitor. Mutator has default set to 105 which works well for 16:10 and 16:9 screens.
New version is currently uploading and should be available soon.