I know these features have probably been requested in posts before, but I'll still write my thoughts on them anyways.

1. Private Messaging

Private messaging is important for any social media. The most important type of posts that suffer from a lack of PMing are giveaways and trades, as some giveaways need to transfer things like keys or whatever. There is Steemit Chat, but that's not connected to Steemit, so impersonators of users can exist.

2. Better curation for new users

Currently, it is pretty difficult for a new user to get their post seen by that many people. Their post with low views won't show in trending or hot, and due to the large amount of content produced, will very much be buried immediately in the new section. They can promote, but most people do not wish to spend to get their post seen. And since they are new, they have no followers to see their posts.

Basically, the only way their post will be seen is if they post it in a tag that quite a few people check, but not many posts, which I'm doubtful exists.

3. Recommended Posts

Seeing posts related similar to ones you commonly look at would be a nice feature to improve user experience, and discoverability of posts.

Thanks for reading! Would love to hear your thoughts, and what other suggestions you have for Steemit's future.
Remember to upvote and resteem if you enjoyed!