I'm not sure if you have completed your survey, but I took a look at it and feel it is not objective nor does it really address the issues in which you ask. There are far more reasons why a person would "not hit a ball straight" than grip, racquet, stance, or coordination. Swing path and timing are more of an issue than those you listed.
There were others too that makes me question what you are really trying to survey.
Let me know because I would like to help but feel that those particular questions were of little to no help in terms of determining the reality of those issues you bring up.