I just crossed 2K reps in SO and hence gained edit access to others' posts. Straightaway I edited a couple of posts to correct spelling mistakes and code errors (and to test my 'editing powers', of course). I am a little reluctant about editing posts for reasons that are not as straightforward as these ones though. Now, I read that it's okay to "Clarify meaning without changing it" but it also says "Always respect the original author". I just changed the title of this post to clarify it's meaning better. Could someone check that and tell me whether that falls in the "clarifying the meaning" side or "offending the author" side of the wall? Of course, offending is subjective and varies from person to person - I'm looking for a general idea (and a second opinion on my first nontrivial edit, I guess).
I don't think your edit went far enough -- although it was as far as you were comfortable going.
The good thing about Stack Overflow is that we're able to make it a repository of perfectly worded good programming information.
Editing is a key part of that goal.
If you look at my edits, they are usually expansive, but I rarely encounter apprehension towards my edits; if anything I've noticed that bad questions tend to get upvoted after they're extensively edited well.
Don't be afraid; just be sure of your edits before you make them. I know I've inadvertantly changed the meaning of a post once or twice.
It's easier to ask for forgiveness than permission (according to Python - don't know if I agree). If you think it's clearer, edit it. If the OP disagrees, he/she can edit it back (or just rollback), but I think most of the time they'll understand that you're just trying to make it a better question and work with you rather than against you.
And edit wars happen, and it's no big deal, because after a few back-and-forths you (or they or some clearheaded third party) realize what's going on and stop (or break it up in the case of the third party) and then it's over. Sure, it's bad, but it's not "end of the world" bad. Just "try not to" bad.
If you lose something in the meaning, or if you mess something up, it's not like it's broken forever. It's just in the permanent edit history for us all to laugh at you at. :P