all pages in mojoPortal are dynamically created so I have no idea what you mean by dynamic pages.
I've told you before you should not map any page to default.aspx because that page serves all CMS pages in the site and it already will serve your home page if no pageid parameter is used. You home page should be mapped to something like home.aspx
mojoPortal just delivers html, css and javascript to the browser and the browser does all the rendering so you need to use client side tools like Firebug to see if the correct stuff is being delivered and you need to understand about how css is cached if you make changes in css.