Action can be way worse than inaction, if what you end up doing is misleading yourself or doing harm to your cause.
I don't think what you've done is necessarily misleading or harmful, as long as you don't consider it anything more than incomplete, qualitative research into the range of responses the word "rationality" gets from random people.
But you really, really need to decide what the point of this exercise is. Are you trying to gather useful data, or make people feel more positive about rationality, or just get comfortable talking to random people? It kind of seems like at the moment, you mainly want to find post-hoc reasons why the exercise was "useful".
Here's my suggestion: if you're trying to do a survey, decide on your demographic(s) of interest. Get everyone on Less Wrong to ask around until they find a sympathiser who works in a branding/marketing survey organisation, and can slip in an extra question in a survey, asking how people respond to the term "rationality".
Failing that, collaboratively draw up a proper survey protocol and get Less Wrongers to administer it to a random sample of a people. Think it through before you do it: e.g. stopping people outside on the street would be more representative than limiting it to a certain building. You could signal that you're an official survey person by carrying a clipboard (not by wielding a recording device). You could improve participation by stating initially that you only have one question which will take 15 seconds, then not trying to start a discussion. You could improve participation among younger women by making it clear that you're doing a survey, so they're not concerned you're trying to start an abstract philosophical conversation as a pretext to get them into bed.
I think this could have great potential, especially if you comparatively test alternative terms to "rationality". Richard Dawkins tried to popularise the term "Brights" for people who don't believe in the supernatural. If he'd done even the amount of field testing you have already done, he would have realised it sounds unsufferably smug. So I think your impulse to do market research is a good one.
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.
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: