You can have a great relationship if you don't have a lot of common interests, but there probably should be some. This way you can each do your own thing but also do some things together. I agree that shared values are even more important, but you also want to have something that keeps you wanting to see the person other than physical attraction. In my experience, having zero common interests doesn't bode well for the long term. Long, awkward silences in the beginning of a relationship is usually a red flag as well. Comfortable, shared silence is totally fine. However if silence is awkward and due to the fact that you can't find anything to talk about, I'd say it's not a good match.