That's a good point, like I said it's just a proposal and would need to gain public support.
> Should we make a law making it illegal to draw pictures of Mohammed, since that offends some people's religious sensibilities?
Nope, because that limits the speech of the drawer.
However if a large group of people objected to the government's use of the word crusade to refer to say some kind of program called "crusade against hunger", I wouldn't have a problem discussing changing it from "crusade against hunger" to "fight against hunger"
The key difference is no one's rights are being violated, the government is just changing a word.
If the government stopped referring to policemen as policemen and policewomen, but started using the term police officer that's fine with me. It doesn't affect what I do. It doesn't stop me from calling them policemen and policewomen.
The name of the civil contract is obviously important to people on both sides of the issue. As you've pointed out, many people have trouble distinguishing between the legal definition and the religious one. Those people are no doubt going to be upset that the government is telling them they aren't "married" anymore, but only "civil unioned" ("civilly united"? There's another problem, it doesn't verb well).
Even if this compromise would be acceptable, the government has no business rewriting laws to cater to certain religions. That's pretty much exactly the thing America was founded NOT to do. We even wrote it into the first amendment. Should we make a law making it illegal to draw pictures of Mohammed, since that offends some people's religious sensibilities?