Why`s Padang So Hot

I would think that after 4 billion years the thing would stabilize and cool off. I can't imagine that this is all due to continental drift and what not. Could there be an enormous nuclear fission furnace at the center of that iron core? Does solar wind drive an electric current in the center that inturn encounters resistance thereby produces heat?

I'm not a scientist or engineer, merely a 2nd year English student. However, I believe that fission of uranium
contributes substantially. Note that we still have radioactive materials at the surface, and since they are so heavy, so we would expect to have a lot more in the core.

I think too, that tidal friction contributes. The earth is squeezed back and forth like a fistfull of window putty as it rotates.

Here's a related thought. If the Earth's internal heat was appreciably greater or less than it is, would a technological society be possible? If less, we wouldn't have the forces that bring iron, lead, gold etc to the surface. If greater, things would be too geologically unstable. Or so it seems to me.

I'm not going to carry this on too far because 1) I don't think either of us is a physicist and 2) our approaches are so different that I doubt that we will come together.
Thinking out of the box leads to creative solutions, but it leads to many, many more wrong answers than right ones. In fact, logical analysis in general leads to many more wrong answers than right ones. That's why R&D is so expensive. Most ideas don't work, regardless of the intelligence behind them. It's also the reason that the ancient philosophers were unable to decipher the nature of the world. DaVinci had a beautiful explanation of the nature of image. So close to being right but he didn't know the physical nature of light and darkness. I appreciate your intelligence, but you seem to trust your own intellectual analysis over the consensus of experts whose conclusions are based on evidence, not to mention a much deeper theoretical underpinning than lay persons can attain.
Questioning is creative. Falling for your own conclusions is a dead end.

Also, some of your concepts seem a bit fuzzy. For example, "erratic movements" inside a raw egg will neither appreciably add to nor subtract from the rotational energy. i.e. they will reinforce the rotation as often as they oppose it. The reason the raw egg slows down faster is that the liquid core did not reach the same rotational speed as the shell. I suspect that if you spun both eggs at a steady speed for a long enough time before releasing them, that both would spin for about the same length of time. There's a little tabletop experiment that might be interesting to try!

Remember, everybody is wrong about everything, it's only a matter of degree.