SN is a fairly new site. It's possible that you may have that option in the future. In the meantime, look what @grayruby is doing with his daily sports post.
I see this as one of the future steps (an important one I must say).
As a fan of decentralization and interoperability, I would also see some kind of integration with the "lemmy" federated network as a big plus. The benefit here is that SN would be the superior tool in the whole network.
Yes, it's very important. For now it's impossible to filter content in different languages. If we have option to create communities, would be a lot easier to bring people to stacker news.