I have put together a work order system using Linux, Apache, MySQL and PHP and I am a bit confussed if I would be better of with XML the a template based system. The work order system is running good how it is now but I would like to do a rehaul of it to clean up some of the code (Try to be consistant) and I would like to make it easier to and new features.

I thought by seperating the html and php that would one way to clean things up and make adding funtionality. But after doing some research it appears that some feel XML/XSLT is the way to go. But I have a few questions.

Do I use php to pull all the info out of the Database to generate a XML file then use XSLT to generate the html?
What happens to the XML files?
Do I just leave it on the hard drive incase some else needs that info or do I rebuild it every time?
What happens when the Database updates do I up date the XML files?
If that's the case why would have the same data in two places?
I am sure querying through a bunch of XML files is not very efficient?
Is XML the way to go with this type of application?
Is it the way to go for a CMS?
If so how is XML used in these cases?