As a side note, the drawing attached to this article is of Edward Tufte's quality, so much information condensed into a simple-looking drawing and it's so easy to get the idea from a single glance.
I'm actually pretty confused by that chart because the bigger planets of SOL are off the side.
The planets detected by Kepler will tend to be unusually close to their star due to its detection method. I believe that’s why Sol looks like an outlier in that regard — it’s really that the other systems are the outliers.
Could be. Detecting smaller planets further out is less and less likely.