I guess it will be difficult to leave beta. Obviously this isn't in reach, yet.
Please have a look at http://blog.stackoverflow.com/2010/10/when-will-my-site-graduate/
Questions per day
15 questions per day on average is a healthy beta, 5 questions or fewer per day needs some work. A healthy site generates lots of good content to make sure users keep coming back.
I think most relevant questions will be asked at some point. I also think it's better to have answers before the questions get even asked. It appears to be more healthy if all questions of a user are answered and he/she hasn't to come back.
avid users vs. total users
Every site needs a solid group of core users to assist in moderating the site.
Maybe doable, but there are probalby more new users asking, than "older" sticking around and answering them.
2.5 answers per question is good, only 1 answer per question needs some work. In a healthy site, questions receive multiple answers and the best answer is voted to the top.
I think questions answered by you, Runa, or other Tor Assistants or people close to Tor wont need another answer. In general, for many questions regarding any topic, I think answers should be given in such a way to create the maximum possible outcome.
(For example, related to Tor, a question about the supported OS/device/platform could be answered with all platforms supported by Tor and forks/alternatives for, let us say, Android.)
The Q&A sticking in beta forever is my great concern. (and I also don't understand why the Q&A is handled by a third-party [SSL being worked on], especially with exposing users to Google and Quantcast/Quantserve, while having a Q&A available)