Communities are not even a blockchain feature. They are planned to be implemented in hivemind as far as I know, which is a layer on top of the blockchain.

SMTs development isn't finished and I don't know when it is finished, although supposedly that is the next thing to be worked on.

As @baah noted, this particular issue (downvotes) isn't a major coding task either way, but there is a lot of support for some ways of improving the function of the Steem economy.

As far as trying to put percentages on specific features I don't really know. I think it is sufficient that developers don't waste their time on things that have little chance (and that has happened in the past) but I don't really see that here.