I didn't find my file review all that helpful... it was a bit... er, cryptic? But, I realized a few flaws on my own. First, I re-evaluated my letter of reccomendation writers and decided that someone must have written a mediocre letter since my file score was so low. So, I switched things up and found a new writer that I knew would tell the committee why they NEEDED to accept me. You want someone with 100% faith that you will be a benefit to the profession, and you want them to state that in your LOR with some passion.
Next, I looked at my personal statement with a very critical eye. I wrote a new one, and I had like a million people read it. 🙂 I did NOT write a summary of my experiences this time. I talked about the most important experiences, and about how they sparked my interest in more specific areas of vet med. I also very carefully defended my interest in pathology, with or without a PhD, and made it clear that I would really consider my options during school to make sure it was right for me.
Now, there's not a magic formula for a PS, but unless you have at least a dozen critical eyes on it, you might not be presenting yourself as well as you could. Take advantage of this forum and participate in the annual 'PS tradeoff' that inevitably happens each summer.
Finally, I practiced interviewing quite a lot. You don't have to do mock interviews the whole time (though I certainly recommend doing at least one)... I got a lot of practice answering questions for my mom, my husband, a good friend. Despite knowing them all really well, you still get anxious when answering the interview-type questions. You can realize in advance that you would rather phrase something differently, or if an answer you were planning to give actually sounds a bit naive or silly. It was really helpful, and allowed me to be 'myself' during the interview instead of an anxious mess.
Anyway... I definitely think you should do a file review wherever you can (some schools will do them over the phone too). But, you should also look at your application with a critical eye on your own.
Good luck... it definitely sucks, but if it's worth it to you in the end, then you should go for it.