I'm actually scared of the 3rd thing you stated out. Steemit seems to be perfect now. It is a bit messy and it lacks perfect UX, but the 500k people here right now seems to be enough. It's a community that you can really take a hold of and get to know a lot of people here.
When the boom here hits, well.. there will be much more people with talent left unknown. It will be a mess.
But then again I am waiting for more people to join. I just hope they brign good content and not spam with them. :)