Go for it! You could pitch it to your local tech as something like "All about England" with a description like "Do Bank Holidays have national or religious significance? Is there a Great Britain football team? What does Hearts of Oak mean? All you want to know about living in Britain and what it means".

If you use the first three or four questions, people will recognise it as a 'dog-whistle' description! (The questionnaire sounds more like it's about being English than about being British, hafta say…)

A kindly Christmas gift, or perhaps loan, I'm not sure, is a book called Fluent Forever which claims to teach "How to learn any language fast and never forget it". I'm reading it with interest.