It would be nice if we can add a question answering functionality to steem, something like qoura, should not be hard.
Also it would be nice to add privacy support so that users can decide which posts are public which are not something like lists in facebook, it's achievable by encrypting private messages with symmetric keys and share the symmetric key with the list (one by one encrypted with their public)
Quora-like system is just matter of UI, feel free to create such :-)
For now, take a look at ChainBB.
As for privacy, it's not what Steem is designed for at least in his current shape. There was some basic implementation of private messaging (messages encrypted with memo keys), but that's not really a good use case for a blockchain based storage. Something that you would like to keep private shouldn't end up written permanently on the blockchain. Once your private key would be compromised, anytime in the future, all your past privacy is gone.
exactly, UI can take this thing to the moon, average users don't understand block chain but if they could find the answer of their questions on steem when they google it, assuming that it will be user friendly enough they would appreciate it's potential. it would be nice if such developments could be crowdfunded by steem users themselves.
Of course they can be crowdfunded. Directly by transfers or indirectly by upvoting posts related to such projects.
about privacy you have a point however it's much easier to give up your facebook pass than your private key, assuming that facebook has not given all your privacy up to NSA already LOL.