I have given my fish fresh seafood from my grocery store before. I had no problems with it but was told if I feed my fish fresh seafood I shold boil it first. I guess if the the seafood has something your fish can pick it up if the food is not cooked first.
Well I have known people just to make a business out of their roses, but be careful, I have found that they split due to stress so it is not always the best thing. I do not know any hard facts, but I know people that get rid of them because they split too much. It always cracks me up though for the ammount that these things split they are still expensive!