I'm just curious here, since I seriously doubt I'll ever actually go past level 10. With the rules in their current state, though, what level you are doesn't seem to make a huge difference. Monsters don't have levels, your HP doesn't increase when you level up (unless you add Constitution, in which case it goes up by one), and your stats are capped at 18. Given that, how much of a difference would it make if you went ahead and leveled up past 10? You should still have some advanced moves left over to take, and you can keep on getting new stat points until somewhere around level 30. You won't be getting any new spells, but you will be able to prepare more of them. This'll break down eventually, but I'm pretty sure you could go to around level 13 or 14 without having to change anything.
Thoughts?