Well, it is indeed a problem. I used to use resteembots all the time. But as my feed is filled with resteems, I find it less and less valuable.
You're suggestion to add something or a mood or anything to a resteem is a very good idea!
I've never had a resteemabuse with altered content, so that's really not an issue for me, but it should indeed be possible to undo a resteem.

Good work man, hopefully it gets picked up!