Many of these options are just plain blocked out - you can't enable or disable them at all. Is that hard-coded, or is there a way to change it? I'd rather have my Open spells be on touch than target, but evidently I'm not allowed to even set that in the CS.

I just tested this. I was able to make a Open Needs a Key Lock on Touch. I made it as On Target in the CS, then used TES4Edit to change it to Touch. I was going for a Open Very Hard Lock but apparently Magnitude 100 is Open Needs a Key Lock.

EDIT: to forestall questions, I tested it ingame and it used the touch animation, and opened a Hard lock (S'krivva's door).
EDIT2: Here's a link to the test mod I made, to allow others to reproduce my results: http://www.tesnexus.com/downloads/file.php?id=31487