I thought I demonstrated this in the beta :-p Yet, here comes another thread wondering why there aren't any. That's because they are easy and lame.

1. Run to the end of the level.
2. Kill only what you have to.
3. Have good weapons.

You forgot:

- Glitch out the spawns
- Stand on top of rocks while time-based events go by
- Network-glitch bosses' movement

;p

Well, technically it wouldn't be a speedrun if they stopped to kill everything. I do that as it is in a Strike, and I'm always left behind.