I've had two experiences with imports into Moodle.
1). Initially we loaded a ton of questions into Moodle when we first started a few years ago with a program we found (Respondus 4.0) that helped a great deal. We were able to copy our questions from our previous system into Respondus and then import them into Moodle. I believe this program has other uses where a instructor can write questions in 4.0 and then import them into Moodle. In this event an instructor could get questions the way they wanted them and then move them to Moodle. (Maybe an instructor does not have rights to the question bank System and develops questions on their own computer and then submits them to be imported). However, we used the program as a one-time tool. This program does not allow an instructor to manage the question once in Moodle.
2). I've found that Access cannot be imported directly into Moodle. In my version of Access you cannot save a file as a CSV. You have to run it into Excel and then save it into a CSV file, then import it into Moodle. I've never tried to import a question but we export our student enrollments from Access-into-Excel, then save as a CSV file, then import into Moodle.
Not exactly what you asked for but maybe helpful.
Mark