That's a quite smashing L. Red Green and Blue with some finely crafted images to match.
However, conceptually, having no links to other pages means you're creating a single web page - that is how the Internet started out, so it's not particularly unique. Having multiple pages would imply that it's a website - which is what most people go for these days.
It's not just because it's been accepted as a norm, but because the browsing habits of humans have evolved from using the single page table layout to a neatly structured page hierarchy - so that's what people expect and are used to - allowing for ease of use.
The single page setup does not allow for much flexibility when you want to add new topics or subjects to it since you'll end up filling up the entire page and then some just with headings - with a lot of information people don't really want to see/filter through. It's all about categorization really - and for your benefit, manageability.
It's much more acceptable to me (talking from a personal point of view here) to click on a link that opens a new page/uses the current page, than to have to scroll down, down, ... until the page decides to die a scroll-bar death. Which is where the popup concept isn't a bad idea - but give the visitor some overview by way of a little thumbnail interface - as already stated. Most pop-up blockers intercept popups that aren't a result of a user activity or due to scripting. However, nothing prevents you from using a standard toolbarless window link for that. And it seems that your scripting engine/compiler tries to refresh the start page or something?
And if you want to get technical, you already have links on the site - so you might as well do it proper and get away from the popup poo-poo. Have fun in your redesign - growth is part of every process because nothing can be perfect. Unless you made it in Photoshop of course.