Kogasa: Just being upfront about this, I will NOT be getting that ZUN CD this time. Besides, your Akibaoo order alone will go over $400 shipped. While it's entirely possible you could save a fair amount if they do have them at the event, you're going to need to rethink this if that's your limit.
I only know the US to JP size conversion which is JP is one size smaller than US (JP XL is a US L, etc.) so I can't say for sure. You might want to take out another set of CDs though, and there were quite a few Rolling Contact CDs that had low stock levels, so maybe you should prioritize those instead. At this point, I'd be able to buy probably all of the store stuff, but none of the Comiket stuff. You might be underestimating the strength of the yen just a tad.
Alusan: Yes, that Fractaleline post means that he won't be able to make any more copies of his older works. He might be showing up as a guest to another circle, but he will be at Fall M3 more than likely. As for the rest of the stuff, $160 should be fine.