Looking for advise to port legacy html based app to Flex 3 based application

Hi
We are planning to port our html based web ui to Flex 3 platform. I was searching for Flex based MVC frameworks and landed here. Read good things about PureMVC.

Our existing web ui has around 70-80 pages with lot of front end validation and custom code in it. It is using home grown framework. Some places we used Ajax, but mostly CGI based (i.e Load a page after invoking an action in the backend).
The web ui is laid out with main horizontal nav bar listing major functional areas. Once you click on one of them, there is a vertical navigation bar with links for sub pages that fall in the major area. Once you click on one of the links in the vertical navigation bar, lower right area loads the page corresponding to that link.
Each page has page specific logic (validation of data etc). But the navigation bars hold global data that is applicable to all the sub pages (i.e sub pages can access or modify these state variables).

I have couple of questions about PureMVC/Flex framework.

1) Once I am done implementing the whole application (with all the 70-80 pages), will that be one swf file or is it possible to separate each page into its own swf file?
I like to package them separate, because user won't have to spend lot of time downloading one big swf file. If I do that, can I share common state in main swf while hosting different swf files in it?

2) Is there any example that demoes these kind of applications (i.e applications with many pages that share state among different pages in a model)?

I appreciate your help.

Thanks
Videoguy