How important is the Premier league to the UK economy.
What are the sources of income internally and externally (from abroad) for UK premier league. How much money comes from overseas to float the big spending Premier league clubs. Domestic TV money, overseas TV money, ticket money vs. stadium debt
Compare financial accounts of the premier league clubs from 2000, 2010, 2020 to see the growth changes
I also think a fun one would be to look at some catastrophic cases like Sunderland where you could take a forensic accounting analysis of what went wrong and how they can plummet two leagues in two years.