I have some Douglas Fir I'd like to use to make a cutting board. Good
idea? Bad idea?

TIA,
NL

A bit tooooooooo soft.


Theoretically, probably too soft. Realistically, probably fine, as
long as you don't expect it to last many generations. I know maple
etc. are supposed to be the best cutting board woods, but my parents
used a "cutting board" for 10+ years that I made in jr. high shop
class. This "cutting board" was a square piece of CX plywood. It
used to have 3/4" dowels countersunk into it as legs, but those fell
off almost immediately after they started using it (now I know the
countersink was far too shallow, and gluing end grain doesn't have any
strength...). My point is that CX ply isn't ideal cutting board
material, but it was functional.
My advice - make your cutting board, use it, and learn whatever you
can from the process. If you at some point get some maple, walnut,
and/or cherry scraps, make a new cutting board (any combination of
those woods is beautiful).
Assuming you're gluing up pieces, I'd definitely use something
waterproof like titebond 3, gorilla glue, or epoxy. They're all "food
safe" once they cure. Use mineral oil as a finish - you don't want
something that hardens, as that could chip as you use it.
Good luck and have fun,
Andy