Hello,
I'm Serhii Kniaziuk (Ukraine +2 EEST)
I can write a wordpress plugin which will convert pages into posts with the correct listing/ categories and subcategories.
Also this plugin will automatically add redirects from old pages urls to new posts urls.
The plugin will store this redirects in db. So, the plugin must be activated till these redirects are still needed.
The full work will take about 4-5 days.
Now shortly about me.
I'm 10+ years php/js/html/css programmer, including some experience in base design and strong knowledges in "psd to html". I created more than 50 wp-plugins and customized hundreds.. (if not thousands) I'm new enough at freelancer.com (about five months only), but already developed and customized more than thirty wp-plugins for clients from freelancer.com and it seems they were lucky that had hired me. You can check feedback in my profile -> "recent reviews" section.
So, if you are interested in my proposal, be free to contact me.
Thank you