Hi Ben,
sounds interesting for me. I am doing my Master Thesis in sociology. I try to "explain" the micro-level vote decisions in admin votes in the german Wikipedia based on quantitative data about there participation and interaction.
I don't know the "right way" how to survey in en.wikipedia, but I guess there are subsites of wikipedia where surveys are announced. Direct invitiations on many user pages will be sanctioned, as far as I know.
Greetings