The EPA rules are a little hard to understand with this type of building. I had a similar job earlier this year and called my local (Denver) EPA office for help. The main question that will came up pertains to children; is there a daycare center on the property? In my case the answer was no so the laws didn't apply. I was doing exterior painting on the church so this might be a different situation.
Give your local EPA office a call and also call your local health department.
Dulling glossy surfaces can also be accomplished with a liquid deglosser. Paso is my preferred brand, you will need to find out what is available in your area. Wet sanding/scraping is also another option.