1) Yes, raids spawn in areas you're in and built up if no work benches are nearby.

2) No. Workbenches and fires provide a "no-spawn" zone. Mobs can spawn outside that zone and attack you. If they can't get to you, they attack any unprotected buildings and farms. Place a fence or wall around your farm. That should protect it.

You haven't lived until you've had some fulings spawn inside your base at night. Ah, fun times. Found out I had a 1 meter area not covered by a workbench. Had to activate an older toon to get rid of the little snotlings.