Yes
Downvote button next to the upvote one that cannot go below 0 rshares (hide content)
List top votes with downvotes at the bottom. (less visible)
We could extract some very valuable curation from the few downvotes that may occur.
It won't affect the reward distribution or "people exploit the rewards pool" until there are cheaper downvotes implemented in the form of a separate downvote pool that doesn't take from your upvoting power.
If the downvote button is next to the upvote button, then I think it's certain that some of the time (even if it's less than 1% of the time) people will click the wrong button by mistake. I would consider it bad User Interface and Experience design. If the buttons are not at all close to each other, it would be much better.
Each side of the reward amount was suggested.
That's close enough for people to understand they are related.