Also, the DRAIN SPIDERS got a new more random movement set so they should more easily find a space to which they might jump, and hopefully not corner you otherwise.
EDIT: I've also re-ordered the KEY script, because your receiving multiple [EMPTY HANDS] means it is definitely doing the script, but maybe not all of it...for whatever reason. I've put the GOT KEY switch at the top now, so if you get [EMPTY HANDS], you should also have the key switch on, and maybe it will even work.
EDIT 2: Installer re-uploaded.