"...the original versions are still stored on the blockchain..."
Yes, yes they are. That is the key which, for me, overcomes all objections to editability.
Writers live and die by their reputations. If you use this ability for evil, your reputation will suffer and your impact for evil will diminish. Watchdogs will be able to unequivocally display your perfidy.
Of course, some of the scenarios you've described are open to moral interpretation.
"Or just leave a tiny teaser paragraph."
I would maintain that this could be an entirely legitimate option, redirecting the "hoi polloi" to Amazon or wherever you may care to transact, exchanging your valuable wares for Steem or SBD.
In other words...
This is the best frickin' thing to happen on Steemit since,
like, for-EV-er!
It's all good!
Thank you for an outstanding comment! :D