I think one item I would like to improve would be putting kind of an AI engine that see whether the comments posted are actually of any value or not. I see that many members with high reputation score and steem power get a whole lot of upvotes, for just writing thank you or nice like comments. I don't think that is something which is worth upvoting.
It is better to upvote instead of just righting a one line comment.
If there could be a way Steem can strip or filter out such less value comments, it might be a good improvement.