Things like this always make me think economics vs. complexity. the last time I did something like this(culinary school) we divided ingredients for purpose. Cheaper whole crab (low meat yield: blue crab for us) was cleaned, roughly chopped, sauteed, and simmered with a bouquet garni, as Suzanne and Cape said. A lot of flavor comes from the shell and all the little bits you can't pick out unless you are an expert crab picker. I was amazed how much flavor came from shrimp shells and heads the first time I made a stock from them, and it is the same idea. And the Brandy idea expands it from just water based flavors to alcohol based ones as well.
After you strain the broth, add the rest of your sauce stuff: sweated onions/garlic, tomato,nice lump crap, herbs, what you remember, and you should get crabby crab. So you won't be crabby. Good luck.