Most doors anymore are pre-hung. They show up at the job site already in a frame and the frame is attached to the wall opening already in place. How well it fits is unknown unless you watched your home being built. If there's space, the builder is supposed to insert wedges at the hinges and lock plates to form a solid backing. Note the words "supposed to".

I'd suggest 3 inch screws for the lock plates and hinges, you want to reach deep into the wood behind the door frame. Check your doors also, it isn't too unusual for a carpenter to get absent minded and hang a hollow core interior door as an exterior door.

You need to pay attention the the vehicles/people normally in your neighborhood and at what times. Also, the vehicles ahead and behind you on your way home. At either end of your destinations are the most likely times for being accosted by those who may want things from you. Oh yes, keep your car doors locked.

Should you patronize any place with valet parking, you should make sure the only key the valet gets is the car key-preferably the special valet key. That way, they may be able to copy your car key and sell that to thieves, but not your house keys. Once upon a time, at a very ritzy joint, some of the valets-almost all relatives of the wealthy patrons-had a booming business selling house keys to a burglary ring. The burglars were bright enough to allow a long time before exploiting the keys, and may have been tipped about when the soon-to-be-victims were out of town.