for resume and project list, you will demonstrate your language abilities. as to ref letter, you'd better get someone whose english is better than you to write that. how could the officer rely on a ref letter full of grammer mistakes or chinglish like? if you cannot find someone write for you, you have to get someone to review it. ref letter is very very important.

the phrases are exactly the same
in both my reference and resume. I think the officer needs to identify
they are the same things.
My responsibilities descriptions are written according to HR-DC description
but modified according to my specific projects.