I don't know if the alcohol would kill germs because it's not in a terribly high concentration in a cocktail?

Funnily enough I had the exact same train of thought as the OP when I went to a cocktail bar last week! I saw them touching money and then touching the fruit that went into the drink. I chose a drink that wasn't fruit-based, because I can't drink much fruit juice - it gives me heartburn. To my dismay, they popped in a strawberry which they touched with their hands. I was a bit frustrated because it was a pointless garnish. Needless to say, though, I was fine. I don't think it's great that they touch money and then touch fruit that goes in people's drinks, but in practice perhaps it's unlikely to cause any problems. Seems to happen in some cafés, sometimes, too, the server touching money and then food. I don't like it, but I guess most normal people don't worry.

I don't think you should be put off cocktails. I think the risk is pretty minimal.