I think one of the biggest problems for this is where the flag is located. I think the flag should be located at the bottom of the post either by the resteem or by the upvote. If they don't want to put it there for fear of misclicks it needs to be in this area somewhere. I was on Steemit for two weeks and didn't know there was a flag or downvote feature until I accidentally saw it one day. I just assumed you had to be a certain reputation level after someone posted about downvotes/flagging before I was aware it was possible.
I didn't even realize that the flag icon would generate a downvote until this post! Would be nice to have some guidelines on that (it probably exists and I just haven't seen it, yet)
I know right!?