I like the idea of rewarding people for helping others, but:
As you point out, it's incredibly hard to quantify what qualifies, or the threshold.
There's already multiple badges for editing posts. This is essentially the same idea, as you're only supposed to edit posts to improve their quality.
With regard to the cloud tag badge, you do indeed have 100 points in that tag, but you haven't yet met the second requirement of 20 answers. You got those 100 points from only six answers.
From the help center:
As for Strunk & White, this one is confusing because it has some hidden restrictions. For instance, editing only tags doesn't count. I didn'...
Regular badges will not be revoked except in very special circumstances.
How do "badges" work?
Regular badges, however, once earned, are yours to keep. Even if the criteria by which you earned a badge have changed (the post was deleted, you got downvoted, etc.) you get to keep your badge. If you qualify for the same badge again (another post ...
This post only answers the question about Strunk and White
PS: If you want to know the progress of some badges (especially editor badges), go to one of review pages then hover on green bar.
According this query from data.stackexchange, until Dec 7 you just have 56 edits count to badge. Between Dec 7 until now (Dec 10) you have 25 edits. So 56 + 25 =...
Score, here, is total upvotes minus total downvotes.
As far as I know it's worked that way since (almost) the beginning.
To quote from the SE FAQ:
A tag score is basically the combined total of all the upvotes (+1) and downvotes (-1) you've accumulated on answers under that specific tag (votes on questions do not count). Acceptance of an answer doesn't ...