MPhil - Questions

[Marissa91]

Hey folks,
I'm new to this forum and have some questions regarding MPhils/MSC   
I'm studying at an internationally unknown US Uni (GPA 3.99) and will graduate sometime next year. 

I'm really interested in the MPhil International Relations at Oxford/Cambridge/LSE (and also in other political related subjects). However, I'm majoring in Business, and I was wondering whether these unis will reject me because I dont have a first degree in IR/Politics/or in a closely related discipline. (e.g I read that at Cambridge it would be an asset but it is not a requirement). So how does it look with Oxford/LSE?   

Secondly, am I disadvantaged because my Uni is not internationally known? 

Thirdly, I have read that at Cambridge you need to submit a Research Proposal? Are there any websites or books that help you in writing one? At Oxford/LSE you need to write a statement of purpose? What do I include in that? (My intended thesis etc...) Can I find some tips about it somewhere eg in a book? Also Oxford requires to send two essays related to IR. However, since I'm not an IR major can I just write them for Oxford? 

Also how important are the recommendation letters? Do they make/break it? 

 

I think that's it for now Thanks in advance!