Additives to make bread soft and moist?
Recipes will generally call for either dry milk or fresh milk. You can (and probably should) always scald fresh milk. You can freely substitute dry milk (either regular non-fat dry milk or "bakers dry milk") for fresh milk by reconstituting the dry milk per package instructions. You can also substitute the other way (liquid for dry) by replacing an equal amount of the water in the recipe.

"Buttery sweet dough emulsion" is not a bread product. It adds butter flavor and sometimes other flavors (usually vanilla) to sweet baked goods like cakes and danishes. 

Regarding diastatic malt powder, you should check the label on the flour that you're using and make sure that it doesn't already contain it. Most "normal" bread flours are just wheat, but be aware of any mention of malt or barley in the ingredients. Those words would probably mean that there is already diastatic malt powder included. Assuming your flour is all wheat, you can replace a very small portion of it with diastatic malt powder. Figure 0.5% to 2% by weight, don't go any higher than that.

If you're just getting started with bread, look for good recipes first. Altering bread recipes is fraught with peril if you're not an expert.

These sites are good places to start:

http://www.kingarthurflour.com/

http://www.thefreshloaf.com/