A thorough and well constructed submission for this life writing TMA, James. I have given the life writing passage a mark in the middle of Good Pass and the commentary is an Excellent, so your overall grade for the assignment is slightly above the middle of Good Pass.
Your life writing takes an unusual subject and the idea works as a kind of strangely impersonal portrait of the narrator refracted through the lens of his job as an immigration officer. I think it works quite well, but there is more work to be done to enliven the piece and to bring out the inherent drama/tension further. Presently the piece lacks some drive, and this is partly because the inner worlds of the two people meeting are not explored at all, so the characters appear a little wooden. The reader needs to care about them more, or at least care about the narrator more... though it would help to care about Melissa too. And some parts of the narrative need to be speeded up, which means judicious cutting, avoiding repetition.
Another element that needs work is the dialogue. At the moment it is rather too literal, and feels like a verbatim account of the various exchanges. Dialogue needs to be more inventive than this if it is to carry narrative and reveal character. Have another look at some of the pieces in the back of the Workbook that include dialogue, e.g. the Raymond Carver story on pp501-505 and try to analyse what makes the dialogue successful. You might reread the relevant chapter as well: Chapter 9, particularly pp133-138.
Do watch out - your tenses slip around at the beginning and then from being (mostly) in present tense the story falls back into past. I have corrected where I could. I suspect you redrafted and forgot to make some changes.
Also look out for small matters of presentation throughout, and in particular the dialogue layout which again I have corrected in enough places to give you a proper sense of how the conventions work.