it *does* boot now: however, during boot I get the error message "Warning: cryptsetup is unavailable" which is what I got before and is the reason I made sure to enable CRYPTSETUP=y in the first place.
So it seems like right now I don't have a way to get this thing to boot, at least on this machine. I either have CRYPTSETUP=y enabled in conf-hook, in which case I get looping "Nothing to read on input" forever, or I don't have CRYPTSETUP=y in conf-hook, in which case "Warning: cryptsetup is unavailable" means I don't get to mount my encrypted volume, anyway.
Like I said before, it does boot in a VM. Maybe I'll try it on some other hardware other than this laptop and see if I get the same problem.