Do these plug directly into the factory fog light wiring, or do I need an adapter?

These mount at factory fog light points and use the factory connector. No adapter required — the harness is designed as a direct fit for your vehicle's OEM locations.

Does the dedicated switch mount in the cabin where the stock fog light switch was?

The switch harness is included, but final switch location depends on your preference and available dash real estate. Most installs use the factory fog light switch location if available, or mount to a blank spot nearby for clean integration.

Can I run the DRL function and fog lights at the same time, or is it one or the other?

The LED units are capable of both — daytime running mode and fog light mode operate independently through the included switch. You control when each function is active.