About 1), yes, definitely a problem.
About 2), that's true as well, and not only in Germany, and it's like that since the beginning. However, this tool was set up by Sami in 2 mins on a late evening (or similar circumstances) to give something to chew to angry CBD maniacs (me included

). Still, what is more important are the tiles of population these circles gather (and a circle gets a tile only if it covers a certain % of said tile).
So in the end, we just need the same kind of tool, but more advanced / refined:
- complete and clickable links for overlapping airports
- full circles
- tiles impacted and to what extent
- possibly the population in said tiles