If I could change 3 things on steemit. It will be:
1) Stopping the use of bid bots. Bid bots have taken the steemit system and most quality posts are being undervalue with worthless or less valued posts on the trending page
2) The flagging system. On steemit a user with greater SP and reputation can decided to flag another user for no just cause, this is so disheartening. I will love to develop a system where a complaint is to be made and cross check before flagging a user.
3) I will define implement a law of one's earnings will be base on the number of comments he do gives because most users on steemit just make posts without bothering to check on other users blog.