There's nothing wrong with asking 68 questions, as long as they're high-quality questions likely to be useful to other people. And there's especially nothing wrong with it if you've taken the time to provide good answers to other people's questions (as you have).
So I say, feel free to delete a handful of the lower-quality questions you've asked that you don't think will be helpful to others (because they're too localized, for example). I don't know exactly what the algorithm is for an automatic question ban, but if it were to happen, I think you have a solid case for emailing the team and having your abilities re-instated.
I don't really feel qualified to comment on the specific questions you've highlighted, as I know nothing about Django, so this is intentionally a pretty generic answer. But overall, it's quite unlikely that someone with a history of solid contributions will trip the ban by deleting a couple of questions/answers.
That said, don't feel obligated to delete questions just because you've already solved the issue or it seems like a "dumb" question in the first place. Those questions might still be useful to someone else in the future searching for a solution to the same problem. Make sure that you post a good answer explaining your realization of your mistake, or how you solved the problem, and accept it when the system eventually allows you to do so. You only need to delete bad questions, things that are actively harmful to keep around or are guaranteed to be useless to future visitors.
"Good" questions are not the same as "hard" questions. Good questions are those that make sense, address a specific programming-related problem, can be definitively answered, and are likely to help others in the future. If you've asked those, keep them and don't ever feel embarrassed that you asked them. Learning new things in a conscientious and productive way is just as important and impressive, if not more so, than appearing that you know everything already!