When talking about separating the layout from other styling info, I AM keeping the designer in mind. As I said in my previous post - its for the sake of those who come in behind you to maintain the website. Your code may make perfect sense to you, and you may know how you structure you code, but the bottom line is that it is plain easier for others to understand and maintain/change your code if it is nicely divided according to what it does. It also helps you if you haven't done anything with a website for - say - 6 months and need to make some changes.
I have already dealt with this in detail. See the 5th post. Chances are - especially for a 1k+ page site - your host has at least 1 server-side programming language to use. If they don't - then stick the layout information in a separate file from the other styling info. This will greatly ease the maintenance process for yourself and for anyone who has to come along after you.