When I want to flavor my focaccias or bread loaves with spices or herbs, I add them dried to the dough instead of topping the final product before baking. In this way, I don't lose them when I slice the final product and I don't make a mess. As seeds I use sometimes fennel seeds, that I toast before use. As herbs I use oregano, thyme, herbes de Provence or rosemary. All dry store-bought (or homemade mixes of store-bought). Does it make a difference to toast the herbs in a dry hot pan before such use? Would it amplify flavor like it does for seeds/spices? 
 Are whole dried Shiitake sufficient for complete flavour extraction in my stock  Of course! Don't bother cutting them up, as that would make them prone to releasing too much of their flavor long before the stock is ready. 