I just went on Steemit to transfer some Steem into Hive, and I notice that they display the HP of the user beside the number of followers and following people in addition to the reputation, the HP and max voting power is interesting.
They also display a rank I guess based on the SP and / or reputation, that an interesting competing aspect to see your rank, some gamification around it could be nice.
Trending tag still works in the URL, but it's hard to find in the UI, having trending communities is good, but I would also put trending tags in a dedicated box on the main page of a user as not everyone is posting in the communities and finding information by tags makes sense.
Thats all for now, hope it helps!