Drinking a shot is not a tradition when you enter some house here. It's a tradition when you join a party like a Birthday etc. Course if you don't drink (drive a car or just don't drink at all), nobody will insist. In the US movies people who come to a party on cars are drinking beer etc. In Russia we have a zero tolerance to alcohol for drivers. So If you had a glass of 3% beer a hour before to drive a car, you are officially DUI here - say "bye" to your driving license and say "hello" to 15 days in jail (as an alternative, be ready to pay a huuuge bribe). A transport police can stop you at any moment w/o a reason only to check you for alcohol (as we say: "blow into the tube"). So if you are going to a party, take a taxi or use your wife as a car driver, because she doesn't drink
As about the empty wallet, so it's true. Giving someone an empty wallet is like to wish him a bad luck. You should put a ruble (or any other greenback) inside.
The same applies to pets. If you want to give someone a kitten or a puppy, that person should give you a symbolic money in return. Otherwise the pet will be ill or even die...