It kind of seems like at the moment, you mainly want to find post-hoc reasons why the exercise was "useful".
I did use all of those reasons to justify why I thought I should do it beforehand. But I have noticed myself repeating those reasons to make myself feel more justified. (Also possible that my primary motivation in doing so in the first place was the social-skill development one)
In any case, I think your recommendations for how to proceed are good ones.
Another idea - if you can't find someone skilled in market research to do this for you at a discount or free, read a textbook about how to assess potential new brands to help with designing the survey.
Several weeks ago, the NYC Rationality Meetup Group began discussing outreach, both for rationality in general and the group in particular. A lot of interesting problems were brought up. Should we be targeting the average person, or sticking to the cluster of personality-types that Less Wrong already attracts? How quickly should we introduce people to our community? What are the most effective ways to spread the idea of rationality, and what are the most effective ways of actually encouraging people to undertake rational actions?
Those are all complex questions with complex answers, which are beyond the scope of this post. I ended up focusing on the question: "Is ' Rationality' the word we want to use when we're pitching ourselves?" I do not think it's worthwhile to try and change the central meme of the Less Wrong community, but it's not obvious that the new, realspace communities forming need to use the same central meme.
This begat a simpler question: "What does the average person think of when they hear the word ' Rationality?' What positive or negative connotations does it have?" Do they think of straw vulcans and robots? Do they think of effective programmers or businessmen? Armed with this knowledge, we can craft a rationalist pitch that is likely to be effective at the average person, either by challenging their conception of rationality or by bypassing keywords that might set off memetic immune systems.
This question has an empirical answer. A few weeks ago I made some effort to answer it. I did not get a huge array of data, but I got enough that I thought I should share it, and I'd encourage others to go out and find their own data points. Ideally someone would make a website that somehow sorts that data (and in the process hopefully get a more structured experimental setup, since mine was rather freeform.)
I work in a tall office building in NYC. Each day, I ride an elevator up to the 30th floor. At least some of those times, I find myself alone with people for 30 seconds. I started asking those people what they thought about " Rationality." My first encounter went like this: