A bit late to the thread, but here are some of my ideas -
1 - There should be a more visible follow button, with the same style as the promote button, making it easier to follow user's instead of having to click the drop down menu from their name.
2 - When reading posts, the upvote button should be placed on a scrolling bar that follows the reader down the page, anchored to the bottom, so that upvotes can be made without having to scroll all the way to the bottom.
3 - There should be an inline image and video expander that allows the pictures and videos in a post to be viewed in an album from the main page. This would be useful when the article is mainly focussed on a single picture or video, so that opening the whole article in another tab is not necessary.
4 - The curation algorithm could be changed such that a post's payout varies with a lower power than its current (Voting power^2), this could be changed to (Voting power^1.5), making content and curator rewards more evenly distributed, while still being resistant to sybil attacks and bot votes.