That's why ASE is quite limited and is not a solution if you want to make an application like you see on the android market. It's more for testing or running scripts, no more.

あしたはにほのごのクラスがあります。 Shouldn't this be: あしたはにほのごのクラスがありません。to match your translation ("There will be no Japanese class tomorrow") ?

Doesn't it hurt just because your brain is 'working/learning' ? Can't we explain this by saying that your brain is tired, after getting so much input?
I have the same problem as you, but I don't feel it as pain. I get much faster tired, that's right, but, I think it's just normal. Hearing is not a passive thing, it should be active, and making you tired means something is moving/changing in your brain, which is cool...