I don't know if are empowered legally or not. However, they certainly DO regulate what private property owners can do and what products they can purchase! Right off the top of my head I can think of Diazinon and Creosote that are no longer available to homeowners. I also think you've forgotten about wetlands, “endangered” species, etc regulation!
You forgot, DDT, Chlordane and PCB’s. We can’t buy those things because manufacture/distribution is outlawed. If they were available, we could buy them. (I have my own private supplier of cuban made Chlordane...and I’m in the environmental industry! It’s Hell on ants!)
As for wetlands, the SCOTUS vacated the last big power grab concerning unconnected wetland on private property. (Connected wetlands -wetlands that cross private property lines- are still owned by the state per state regulations).
Hill Country, huh, Rolf. Us Yokels be from the hills, too.
In addition to your argument take into account that the EPA can and has inserted itself into the inspection and sale of homes. Got mold? May as well tear it down and rebuild for all it will cost you. With the bulbs all they have to do is mandate a sweep of the home that is for sale for even minute quantities of mercury. Detect it and suddenly you are now liable for time consuming and expensive cleanup and reinspection before you can sell. Then again, you can probably become rich by starting a company that specializes in inspecting and cleaning up micro quantities of mercury from the new bulbs by gouging the desparate home sellers.