I am a US citizen, have booked a flight with American Airlines that flies to Tokyo.

With connection through Beijing Capital Airport. Flight plan is as follows:

Dallas, TX to Beijing, arrive at 2:55pm (American Airlines Flight)
Beijing to Tokyo, depart at 4:40pm (Japan Airlines Flight, but booked as part of my trip via American Airlines website)

1. From what I have read, I will fall under the 24 hour transit rule and not require any type of Visa, is that correct?
2. Is that enough time to transfer in Beijing?
3. Do you know which terminals each of those airlines use?
4. What process do we have to follow when we get to Beijing? Do we have to pass through immigration/customs, or can we just head to the next gate for our flight to Tokyo?

Thank you!