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Thanks for the question. First, you're not crazy! Second, I'd suggest reading all of these Moz resources on international SEO, Hreflang, and CcTLDs. They should answer all of your questions. Just a couple of other observations. First, I would divide your English subdomain into two like this: en-us.domain.com en-uk.domain.com (Although, I'd personally prefer to use subdirectories such as domain.com/en-us and domain.com/en-uk.) The reason for this is that you can continue to tailor the subdomain to each location in addition to language. In just a basic example, the UK subdomain may want to have text in British English and show pounds while the US subdomain may want to use US English and show dollars. In Google Webmaster Tools, you can also tell Google that a certain subdomain or subdirectory is targeting a specific country. There are several other things to do as well -- again, I'd suggest that you read the linked documents above. Please feel free to post if you have any other questions!