Will this switch plug directly into my door panel without adapters?

Yes — this is a direct OEM-style replacement. It connects to the factory harness and mounts into the factory switch opening with no modifications or adapters required.

Is this the master switch or just the driver window control?

This is the driver window control switch only. It operates the driver window independently. If you need the master switch (which controls all four windows), that's a different part.

What if the switch doesn't work after installation?

Test it before fully reassembling your door panel. If it's not responding, check that the connector is fully seated on the harness. If the window still doesn't move, the issue may be in the motor or regulator, not the switch.