Q:Does a planet's tilt contribute to it's internal heat?
No, Jim, it doesn't. The internal heat is, for planets, or better has been generated in the formation of the planet by the conversion of gravitational energy in thermal energy (called heat of accretion), by the differentiation of the planet's material in layers of different densities(lithosphere and core for example) or by radioactive decay.
For stars, the situation is rather different. More mass being involved, the heat of accretion raises the temperature so much that fusion reactions become possible on a large scale, and these reactions produce further energy, etc.
Tilt has nothing to do with this, in the sense that seasonal heating it is more than negligible compared to the internal heating. Even for the planets close to the Sun. You compare temperature variations at the surface of say a few hundred degrees at best with tens of thousands of degrees in the core.
But there is something that I don't understand. I know that you are looking for your own interpretation of the solar system, and this is fine. But some of the questions you've been asking are below freshman astronomy, and I belive it would be much more efficient for you if you actually read an astronomy/astrophysics book. There is wealth of such books, some of them presenting elementary phenomenology without too many formulae and theories. If you'd like, I can round up some titles for you.It would be a much better use of your time than reading dkv's aberations like: "There are other factors as well which contributes negligibly but are important."
