If you got a large number of visitors, that is really good. If it don't isn't such an achievement. It is generally good to look at once you get tons of daily visitors, like around 1,000 per day I would say.
I get 5k visitors per day and my CRT is over 4%, so it doesn't really have anything to do with the number of people visiting your site. Just good add placement.
I think it depends on ummm, the ad placement and colors. The right place and color can take you up to 15% or so.
It is a really good click through rate according to me. I get around 1% click through rate and I am doing ok. But your click through rate is good and a bit high.
It depends completely on your traffic and type of websites. Parked domains theoretically have an even higher CTR.