Dr Racket is a horrible IDE.
Routinely uses ungodly amounts of ram, ever try scrolling through your code because it spends 30 seconds in some paren matching loop.
Unfortunately I have to agree here. I abandoned DrRacket for Emacs racket-mode and geiser because waiting for DrRacket to finish whatever it was doing became too much for me. On the other hand, as an Emacs user, I'd probably do this even if DrRacket was much better optimized than it is :)
2 - List based = flexibility, get more done faster because lists are simple and everywhere
3 - Strongly nudges in the direction of functional programming
4 - Rocking documentation, advanced libraries
5 - The Dr Racket GUI IDE
6 - X-expressions (don't know what they are)
7 - Hygienic macros
9 - Easy to write powerful DSLs
10 - Many low hanging fruits to contribute