Spelling out what's meant by all the questions would be a major undertaking.
I know. >_< I have to set milestone goals so that it won't seem too overwhelming.
But I imagine most things you might not understand could be explained by a Google search of the terminology - in fact, a great deal of it is probably on Wikipedia. Anything you still don't get could probably be answered by people here if you make a thread about it (and that would help other people as well).
The problem is not just understanding terms or concepts. Take the first question for example: "Does the language make any difference between direct speech and quoted speech?"
AFAICT, even after Googling, direct and quoted speech are the same thing. I'm not sure if making a thread here for all the questions I have is such a good thing, because I will end up having millions of questions. I think people would just stop replying after a while. Even if I made separate threads for each question.
A filled-out questionnaire for a single language might not be all that helpful, as a lot of the answers are just going to be "no", which doesn't tell you anything.
Well, the good thing about this questionnaire is that it forces you to think and write about underdeveloped parts of your grammar. Even though I'm writing a separate grammar, I might just as well fill out the questionnaire too. It could come in handy if you quickly need to reference something.