Time differences, etc, plus the volume of traffic can delay answers. If something doesn't get answered, just bump it back to the top of the list.
My first comment is the first paragraph- I would change the tone. I wouldn't say things like 'I am at a loss'.
I would like to inquire about your Linguistics program.
(That's all I'd put in the first paragraph)
Secondly, I think you're asking too many questions in the letter. It's a bit of overkill. I'd just ask what the requirements are for entrance in terms of grades, maybe mentioning yoyr TOEFL score and college English. Don't go on about being more interested in drawing- it's not selling yourself. Mention that you are a Korean speaker and are learning Japanese, and ask about interpretation. The best letters are short and to the point. Do details like your age matter? If not, cut it. I'd say that anything that can be cut should be cut. Get the basic details and then start going into the finer details. A very long letter may well not get read and some of the points may simply be missing in the reply.