Let me correct a few things in your blog.
1) you are right that V8 does not provide DOM;
2) Chrome has DOM in the browser because actual implementation is done in WebKit (C++ code);
So, you can not access DOM in a standalone V8 because DOM is part of browser, (think about it is a library, and only browser implements that library). But you can execute your script in Chrome which has DOM binding with V8.
Your original question was to parse webpages with scripts (using V8 as a parser). It should be fine as long as scripts are not running.