1- Haha, it's in the FAQ. :)
2- The goal of @steemcleaners is to try and crack down on that behaviour. Unfortunately, it happens quite often (and is at an all time high).
3- Totally agree. Sadly, Steemit currently incentives short lived content and doesn't have any way to reward old stuff. I wish there was a way, but it's actually quite hard in the current setup to try and solve that problem...