Will this tank work with my factory coolant hoses and cap?

Yes. This tank is designed to use your existing hoses, clamps, and radiator cap without modification. Your sensor and overflow lines connect at the same points as the original tank.

Do I need to drain my system before swapping this in?

You'll want to drain enough coolant to safely remove the old tank and install the new one. Once the aluminum tank is bolted down and your hoses are reconnected, refill to the proper level and bleed air as needed per your service manual.

Is there a finish on the aluminum, or will it oxidize?

The tank arrives ready to use. Over time, aluminum will naturally oxidize if exposed to elements. If you're mounting it in the engine bay where it's visible, you can seal or paint it to your preference, but it's not required for function.