I reckon there should be more Opportunities to earn house points and xp, such as quizzes, polls and minigames, and as well with a more explicit way of saying 'do this activity to earn points/xp'
You can already earn House Points with homework (grading & submitting) and Peeves's Corner. There are even more ways of getting xp (like, logging in on a daily basis, having happy pets, chatting, roleplaying, owling, and gaining house points of course). This should be all explained on your site's guidelines - if not, you can contact your admins to suggest them these additions. Moreover, quizzes, polls and minigames aren't very much related to the Harry Potter canon - homeworks are, in comparison. Therefore I don't believe such an implement would be necessary nor doable.
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