I take that all on board but disagree with most of it. The questionnaire itself is based on work done by other scholars in the field and they have had success with it. For example The Likert Scale styled questions are one of the most popular used in quantitative studies.
Saying MLS is still a Minor Sport is very ill informed, OK it's not as popular as some other sports but I have also had the most responses from those guys and believe within the next decade it will be right up there with baseball and NFL. Also this will help me to compare English football fans with American 'Soccer' fans and then can also compare to NFL fans as another culture. I didn't want to go down the route of comparing loads and loads of different sports but maybe it's something I can think about for the future.
I don't think many of those kind of fans who 'pick and choose' their favourite team will take part in this because I believe they are the kind that wont be that bothered about their team anyway.
Believe it or not I did do research before putting together the questionnaire and am already getting interesting results back. Thank you everyone who has taken part!