Are you still recruiting? If so, I could try.
To outline possible problems:
1) I have very limited experience with WH40K RPGs due to not having many acquaintances who would be willing to play the game.
2) I have never played a play-by-post game before.
3) I am rather socially awkward, and thus far have been passive in RPGs.
4) English is not my first language, and I may be out of practice.
Out of the character ideas that I would like to try in the case of your approval there are a psyker, and an engineer with demolition skills.