I generally don't think of it as a Q:A ratio. In my mind, it's bad if you are noticed in a bad way. There are occaisons when I come on the site and go through the questions and every page there's a question of the type "Do my work for me!" by the same person. When that happens I generally halt my helping of that person.
If you ask well-thought-out questions and it appears that you've put some amount of work into finding the answer yourself, ask away. If your first instinct when you hit a wall is to go leech off of SO then I'd rather you weren't around. That being said, this is a resource for the future so even if you ask a question now for the wrong reasons it may help someone in the future -- so I'll ignore someone's "poor etiquette" if I feel the answer well help others in the future.
Oh, and for crying-out-loud, search. :) Both SO and Bing.
Looking through your questions, I would say that you are a using this service properly.
It may be interesting to know that I, personally, like to get involved with a community and help out before asking of it. I tend to use my Karma as a debit card rather than a credit card. However I in no way hold others to the same standard.