Boo David,
A survey is not that easy to design and then implement. Covering all possibilities is near impossible. Still, the results thus far are interesting to see and the idea is one worth chasing down. Have you thought about recommissioning the survey as I think that those who visit this site would be more likley to complete a more complex survey than that presented? I would recommend a redesign if it is to be used in a paper to support an observation or a finding. {Happy to help}
Anyway, have fun with it and given you are looking at what people do in Astronomy as a hobby, it might be enough without any additional work!
Enjoy!!!
John.