As a new and fellow freelancer specialising in IT on freelancer.com, I can help you improve on your English and business etiquette. Although my name is very Asian, I was brought up in NZ and have native proficiency in English.
Also, as a head start,
"I am beginning IT freelancer and I need an English expert who can ANALYSE my chat history (around 10 projects) to find [my(move -->)] typical mistakes in MY English and business etiquette."
You move the "my" from mistakes to English because its more of a personal thing to do with your communication skills.
Hope I can help you out and good luck with improving your skills if I am not chosen!
Thanks :)