I chuckled at "recovering sexp addict". What possible risk is there in over-indulging in sexp?! I simply don't see it.

Speaking of unconventional lisps, I enjoyed this recently:

https://github.com/vygr/ChrysaLisp/blob/master/docs/lisp/lis...

from Chris Hinsley, author of the (very) cool Chrysalisp operating system. Same author who wrote this in 1995:

http://www.uruk.org/emu/Taos.html