Don't think writing code to build form or report will really be very helpful in understanding how things work.
Creative solution for the cascading combobox. Can't recall ever seeing it or having thought of it.
Instead of building a query object for combobox RowSource, I would put the SQL statement directly in the property.
SELECT ProdID_PK, ProdName FROM tblProducts WHERE IndID_FK=[cboIndID] ORDER BY ProdName;