I'm talking about shillings, and silver isn't a weakness of vampires. Their real weakness is holy silver, which is also called Mythril or Titanium.
No. Same weakness for creatures of the night. Mythril/Titanium are light, durable, and holy. Silver isn't going to help you, because it is an icon of greed, and cannot transmit holy power very well.
Titanium is expensive, so you're better off buying a titanium bit set along with a new drill than a sword made of it.
Also, werewolves don't regenerate very fast, so even a regular sword will work if you swing it hard enough...