Quora app is being developed for Steem already. I haven't used it yet and I am not very interested in that kind of software, personally. I never was. But I salute it and every addition to Steem is welcome!

Very, very difficult to do. This goes beyond the Steem blockchain possibilities for now. it could be changed with a hardfork though! Something I have been complaining about since my first days on Steem. Maybe there IS a way to create a workaround for this. I have some ideas but it is complicated.