I thought you knew that I'm a moderator on Westeros.org, that I've met GRRM several times and interviwed him live on stage in front of hundreds of people. Read the damn book? I read ADWD a month before it came out, and my name's in the damn dedications at the front
For your information, this is a pretty popular and widely-held theory. There are some objections to it, which you have identified, but it's also got a fair bit of support (including from some people who know a lot more about what's coming up than I do).