HELP ! Need readproof my sentences, message is clear but expressions look doubtful to me.

Dear English Forum !
Thank you for this extremenly useful site you doing a great job. I hope to achieve your level of English some day. I see you as a role model for my English studies.
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I am appling to my dream job, there are hundreds of candidates for each position.
Original I wrote in Russian and then translated to English.
I think in my letter there are some "Russian thinkig problems" I do not pretend to be a language expert, but I need my message to be clear and pleasant to read. I want expressions like "Mother tongue" instead of "My native language" be avoided. Those are chosen pharagraphs from my letter that i feel might be doubtful. It would be nice if possible to preserve same tence and pace.

1) I DO NOT intend to offend you by any means. Hundreds of letters start with “Dear Sir/Madam”. Unfortunately, I do not know your real name. I called XYZ office in CITY, but they told me they do not release given names of their employees. I do not like to write impersonal, callous letters and that is why after some search in the Internet I found out that statistically one of the most wide-spread names in China is Bob. Even if I did not guess your name or gender, please consider this letter as addressed solely to you.

2) It is not just that I want to change my job, but I am looking for a place where I could realize my interest in coolant systems.

3) The more complicated is the scheme, more interesting I find to work with it. I perceive all the difficulties as a challenge to my abilities and an opportunity to learn making things better and at a higher quality level.

4) I have an extensive experience in this sphere which is confirmed by my CV. ( Is word sphere really useful here ? Not area , or field?

5) Most details on Bubling Transactions are known quite well to me, both from the your book itself and out of my own initiative (I read in detail history of Bubling Transactions at XYZ’s Web-site and in Wikipedia).

6) Russian is my native language. I wrote this letter in Russian and translated to English to reflect my skill in both languages.My English communication is fluent; At my workplace, it is an official language of correspondence and business communication. I also have a excellent level of Hebrew and practice Japanese. If XYZ offers Chineese language courses I would like to register for it right now! Learning a new language is always useful; besides, that is the language of the country where I intend to work.

7) In conclusion, I would like to add that it is very important for me to learn something new. Teamwork for me is also an opportunity to obtain knowledge; e.g., thanks to my team-leader I understood the difference between Mobile Bubling and Static Bubling development processes.
Dear Bob, I am a quick learner. It took me 2 weeks to master document design with “This program”. I wanted to stand out so much, that I gained this valuable knowledge and I am grateful for that.

Moradar.

P.S Thank you for looking into this matter.