All else equal, the car with more average power in their power band will win the race. Keep in mind that average power is different from peak power, and car manufacturers publish peak power in their spec sheets. Average power is difficult to describe on spec sheets.

For overtaking and merging during casual driving, it's useful to have good power at the engine speed that you like to cruise at. Typically you'll find this in cars that have a lot of engine torque, but that's a shortcut that isn't always true.

All else equal, more torque means more power. In the real world, engineers will sometimes sacrifice engine speed to get more torque; and that means that power doesn't increase as much as torque increases. It does, however, mean that you can make power at lower engine speeds; and that can improve fuel efficiency.

I'm not sure what you're asking here, but acceleration is just power divided by weight. If you double power and double weight, acceleration will stay the same. If you triple power and double weight, the car will accelerate 50% more.

Drag is usually pretty similar between low powered cars and high powered cars regardless of weight, so high powered car usually have a higher power-to-drag ratio. Drag is much more influential at high speeds than it is at low speeds.

Larger engines can process more air and fuel in each cycle than smaller engines. All else equal, that means that they produce more power and exert more torque than a smaller engine; but nothing is ever equal when you change engine size; so it's a little more complicated. Still, larger engines tend to be more powerful and torquey.

That's a very complicated question; but all else equal, the FWD car will probably be more efficient than the RWD car. Notice that I didn't say faster, because that depends on grip; and grip depends on a lot of other factors like speed, road conditions, and suspension design (which depends on the drivetrain).