I think a slightly improved version of Steem World's CSI will work. It would have to change based on size of account. For example the more SP you have the higher it should be to get a green flag and stay out of yellow.

Green means normal account, all is good. Becareful and doublecheck when downvoting/flagging.

Yellow flag would be low CSI. Down votes don't need to be justified because farming, circle jerking, too many subscription votes, bod bots, low effort automation etc. You probably shouldn't upvote these people until they change.

Red would be black listed actions like spamming, cheating, trolling. Even upvoting on these acounts makes one look bad, it should be discouraged. Some can change, many will just create a new account to try and continue their BS.

or red