I think the initial contact would be the hardest to setup.
People dealing in crypto probably like to keep their emails to themselves.
I think an app that would allow an Author to connect to an Editor would be the best bet. And the app could hold the article until final payment is received and then post it.
Interesting, I know very little about apps. I avoid them whenever possible. ;)
Technically, STEEMit is an app. ;)