Coral is the "stone" associated with the Virgin Mary. It is a symbol of purity, which is the same reason as silver. While not specifically a vampire weakness, it could easily be construed as one by ways of reliquaries or blessings. Holy swords (as in those carried by Templars and Eastern Orthodox Priests) are also an Eastern European vampire weakness. Holy ground is also a weakness of theirs. Some lesser vampires turn to dust on it. Stronger ones are severely weakened and vulnerable to attack. Those are the obscure ones I know.
Yes. Also, look up different sorts of vampires. I think the most creative I've come across is one from Malaysia which takes the form of a normal human woman in the day. At night, they grow wings and a long, spiky tongue, split in half at the torso and fly around, sticking their tongues into windows to drink children's blood with their intestines dangling out of their bodies. They're called Manangagal, I think.