That's how I make oat flour from rolled oats, the longer you process it in the food processor the finer it is ground up.
There are a number of King Arthur Flour recipes that utilize products that they sell on their website, the Whole Grain Bread Improver is one of those products. Hopefully the Vital Wheat Gluten and a little vinegar will have a similar effect.
Diastatic Barley Malt is often added to wheat flour at the mill. (Look on the label, you may see 'barley flour' or DBM listed.) It contains enzymes that help break down the starch in the flour into simple sugars that yeast can digest. Yeast contains similar enzymes, but adding the DBM gives the yeast a bit of assistance.
You may also see sources for non-diastatic barley malt. In this case, the barley has been heated to disable those enzymes. NDBM is basically a flavoring ingredient, it adds a nutty taste and a bit of sweetness to the dough. Adding barley syrup accomplishes pretty much the same thing.
'Malting' refers to sprouting a seed before grinding it up. When a seed sprouts, it becomes a chemical factory, manufacturing a number of compounds, including several enzymes, that aren't present in the seed if it is just ground up into flour. So you will sometimes see malted barley flour or malted wheat flour in the grocery store, there are a number of interesting recipes that call for malted wheat flour.
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