Help with Japanese mail

I have a Japanese Pen Pal but his English is just as poor as my Japanese. I really like talking to him but aside from the fact we speak by email so it takes practically the next day for him to answer back due to the time difference, we don't understand each other. This is the last email he sent me and I dont understand it. Can someone please help me and translate this to me in a proper English form. 御苦労様。

わたしは、Claudia さんの日本語で書かれた文章で理解できない箇所がある。
あなたの伝えたいことが、私には分からないときがある。

I cannot understand by the text of the Japanese mail which you sent to me.
That is, the thing which you want to tell cannot understand to me.
I have a wish to you.
I am also intelligible when you write a Japanese text by e-mail, and an English text is also written.

ところで、クラウディアさんは日本語で文章を書くのは得意ですか？
クラウディアさん自身は、日本語で文章を書けるようになりたいですか？
By the way, is Claudia good at writing a text in Japanese?
Does Claudia come to want to be able to write a text in Japanese?

わたしは、Claudia さんの日本語で書かれた文章で理解できない箇所がある。
あなたの伝えたいことが、私には分からないときがある。

"Claudia, there are parts in your Japanese sentences that I cannot understand.
At times I cannot understand what you want to say."

ところで、クラウディアさんは日本語で文章を書くのは得意ですか？
クラウディアさん自身は、日本語で文章を書けるようになりたいですか？

"By the way, Claudia, are you good at writing sentences in Japanese?
Do you yourself want to be able to write sentences in Japanese?"


The two sentences beginning "I have a wish..." is not written in Japanese, right?
I guess he is saying that it helps if you write Japanese text AND the same thing in English text alongside each other.

By the way... 御苦労様 is "thanks for the trouble/care you are taking," but this is used from someone superior to someone lower in ranking, as in from a boss to their subordinate. Please avoid it when you make a request for translation like this :)

I am sorry about that & Thank you for your help!
Sincerely,
Claudia

By the way AK, could you please tell me the proper way of writing a casual thank you such as Domo Arigato?

どうもありがとう is domo arigato (all written in hiragana).

One thing I might add :) When you ask for something, and don't know if the other person is going to do it or not (like when you asked for translation), we would say:
よろしく　お願いします。(Yoroshiku onegaishimasu.)

Once the favor is granted and you want to say thank you (for doing something for me), domo arigatou is correct :)