The first half is certainly true, but don't overestimate the importance of HN. If you want to spend time on stuff that will impress us, it's better to spend it building things than commenting on HN.

Also, I'd say "people" rather than "person," because we care not just about the founders but about the strength of their relationship.

What if you have a much stronger presence on a site like Quora or StackOverflow, is that considered as well?

It seems like all three (those two and HN) are communities where the type of people you like to fund would spend a lot of time.