Jon,

Thanks for catching the ":cv" part - that was it, it's now working even without restarting the server; I originally had "cv"s all over the place, but search-and-replace left this one stray one, and it took your fresh look from the outside to see it.

Got you about the .query.xml file - removed it.

You even simplified the first RegEx bug, that's great.

Regarding the 2nd one, even if it's by design, I say, it's a poor design. It's not just the delete X option that's missing, but also the edit icon (as you properly noted in the bug report itself); it doesn't show up right away, unless you
1) add another RegEx
2) toggle the Required check-box or
3) click on a different field and then come back to the first one

Imagine you're coming back there just to tweak the one RegEx you have, you have to jump through some hoops to do it...