I was going to try and come up with some motivating and inspirational explination of what the world could do with out, but no matter how hard I tried, I kept coming back to the same conclusion: The world would be a better place without people.
Think about it. The reason that we live in the world we see around us today is entirely humanity's fault. Pollution? Humans. War? Humans again. Stupidity? Greed? An insatiable lust for more? Check, check, and check. You cannot find another species on this planet that has left more scars and changed more for the worse than the human race. I strongly advocate the coming of World War III, just so we can blow ourselves to kingdom come, and then whatever strange, mutated lifeform manages to crawl from beneath the radioactive dust can look back on our little shitstain existance and see exactly what NOT to do.
Though I will say I am a fan of the forehead markings in the OP. It would solve a good portion of problems, and would probably nudge humans in the right direction to start fixing ourselves, but at the end of the day its only a temporary fix at best.