None of these issues are addressed in the manual.

1) I seem to keep toggling an Autorun function. When I hold shift with it on, I walk. When I hold shift with it off, I run. I like the feature but can't figure out which button triggers it.

2) Is there a button to cycle thru weapons? I like the feature that auto-switches to the default machine gun when you run out of ammo but I would like a way to switch to the next available weapon without having to look down and remember the hot keys.

Incidentally, making the counters on low ammo orange and red was a mistake.

3) Is there any way to rebind keys? I don't understand why a dedicated suicide button exists, let alone why it's right next to the key for up.

4) The manual say dodge is "z" but it's "f" or right mouse-click.

On a side note, I wish the camera was better. Often when running up, the player moves above halfway and you can't see the people above the HUD.

EDIT::: I've found there are options for rebinding keys and there are, indeed, cycle weapons buttons.

Have you checked to see whether your keyboard or OS are switching into a different mode based on how you're pushing the buttons? This sounds like something which could happen if Caps Lock is toggled, or features such as Windows "Sticky Keys" etc. are active.

I've had confusing input bugs happen where the cause was one of the key combos was switching my input method between non-English languages, which rearranged some of the keys as far as the game was concerned.

You could open a notepad program and when you notice this happening, alt-tab to the notepad and try to type something. If it's an input assistant causing the mayhem, there could also be an indicator icon by your taskbar clock.