To add to what eschwartz already said: if you're going to use dwarf or elf, then do so in order to borrow from people's existing expectations - at least to a certain extent. This does not say they cannot have variations on the traditional theme (eg: your vampires can be shiny
), but the traditional forms are the starting point.
Or to phrase this in the reverse: if you start by calling something a dwarf or an elf then the reader will automatically attach certain attributes that you then have to turn if they don't fit. If there is nothing traditionally dwarf-like or elf-like about your characters then you would be better off avoid using that term.