None of what you've said here makes you stand out from your biggest problem: Imgur. None of those features are groundbreaking or even original. And how are you going to monetize? Running this service won't be free.
I can't comment on what might be right or wrong with other sites, not in the capacity of someone promoting a competing product.
Itsosticky is fast (server hardware permitting), modern, has no advertising at all at the moment, and no third-party sharing widgets.
I can't discuss plans for monetisation - there are none as yet.