The Spycam is used for Cassidys Storyline. When you go to drink a coffee in the office it triggers at some point the investigation. When you reach 100% during that investigation and place the Spycam in the office before the meeting at night with Cassidy, she becomes your pet slave.
The Bike and Car can be used to get to the beach at summer. It costs you less time if you own a car instead of a bike when you want to get there.
For the lights at the house I've never experienced something so far. Maybe it's a preparation for a later update.