I can comment on all of your statements, but I just want to say that you have to realize that there are other channels to point people at interesting content other than the /new link. Whether you like it or not, there are people who link their submissions on any of those channels and might ask to upvote it. Just like it happens on all other communities. #startups is not an organised voting ring. The regulars only upvote/flag/downvote people/submissions if they would do the same thing as if they stumbled on that content in "the natural" way.