Some of these sounds possible...
But in complexity, there's always something big wrong with them. Anyhow, you asked for constructive criticism, so...
I know it's troll physics, so I know the animation's supposed to look bad, but when you're using a versatile program like Flash, there's no reason why you can't add a little bit of flavor to it to make it easy to watch. Also, recycling a poor-quality song kind of induces watchers to ragemute (I did, at least). Lastly, the ideas could have used more work. They were so cliché that it really ruins the value of watching the collab in the first place.
All in all, it was a decent attempt, but requires better effort. And by better effort, I'm referring to the quality level you'd expect from clever trolls.