As a practical matter, with limited data, you can't do A/B testing. You have to just move forward, guessing on each step -- yet carefully tracking whether the change brought an improvement.
I'd say that writing open source is another kind of positive social impact. You can do that in your spare time, but if you can do it on the job, all the better.
For sites like yours, you want users to sign up, not to spend all day on site. Stickiness is important, but your priority has to be customer acquisition, and for that, the design is fine.
Your fellow hackers will always spare a few minutes to talk. Good seeing this go up as a service.