Personal preference. Drinking human blood is a definite no no for many reasons not necessarily stated here, but obvious! Animal blood such as that of a cow/steer is just like any other animal organ rich in protein and other nutrients and really no different than eating steak. It's a personal preference.
Blood. I would not advise it, whether for cultural or other reasons, unless it is clean & processed.
That is viewed. Differently in the context of different cultures and religions. Has the blood been properly cooked?