Set of easy transitional switches for launch day.
No. I had a coworker point me to the article http://www.onextrapixel.com/2010/01/30/13-useful-wordpress-sql-queries-you-wish-you-knew-earlier/ and asked if I could build it into a plugin.
No. Neither the idea nor the request came from me--I simply sat down and coded it to save us some time here. I'd feel bad about stealing IP.
Restore it.
That's on you then, isn't it? There was a very clear warning that this plugin interacted with and wrote over your database. Go in and try and run a query through phpMyAdmin. I based it on the article listed above, so maybe that can dig you out of the hole. Alternatively, if your clicky finger slipped, just click the revert button, which essentially runs the query in reverse to undo whatever you just did.
Email me your ideas to montgomerygraphics[at]gmail[dot]com.