Also, light DME is just lighter in color than other DME. Different manufacturers have different names for their DME, some are useful outside that brand and some are not. Light is a color descriptor that may or may not be lighter than some other manufacturers DME, while Pilsner DME is made with pilsner malt so that gives you some information.
Diastatic malt powder has the enzymes that will break the starch in the flour down to sugar. It helps the bread rise by feeding the yeast. Non-diastatic malt powder doesn't have the enzymes.
But if you want consistent results, you should probably only use malt powder intended for use in making beer. The baking malt powders often (but not always) have additives to help bakers, and the flavor is reported to be inferior in beer. It's an enhancer in breads, it's one of the main flavors in beer.