Disable game features such as the welcome wagon and vampire break-ins

The welcome wagon can be cancelled early by clicking the X button on the event UI in the top left corner. This will give your sims a negative relationship point with the neighbors though.

There is no way to cancel a vampire visit/breakin as far as I know. You could hang garlic around, but I don’t know if that will stop them from visiting entirely. I usually use MCCC on the Vampires that stand outside the front door for hours and make them leave. Otherwise they will stand there for hours and disable super speed 3, which is very annoying.