Curious. How exactly would this work? Would quizzes still work exactly the same... you type in the questions with [FIELDTYPE] and the quizzes would use the fields system (and if so, would it still support only the fields it does now, or would it support any field types that the fields system supports)? Or would making questions work differently and allow for choosing field types on a per question basis (similar UI to adding fields for a catalogue for example)?

Unclear. It would depend what other issues were implemented.

It could be done this simple way.