How do I figure out the temperatures of certain latitudes on a planet with factors such as sunlight and the emission of heat and energy from a planet's interior? Assume the planet is smaller than Earth and is warm enough that even its soil could be 80 degrees Fahrenheit, yet is still cold enough not to lose its oceans. These oceans can have a warmer oceanic crust and should be larger but shallower than Earth's oceans. The planet as a whole should have elevations like Venus with fewer areas of high and low elevation in comparison to Earth. Particularly when the planet has no seasons and should be tropical by Earth standards across it's surface?
Ex: how do I figure out the temperature of the tropics if the poles are as warm as our tropics?
Yes it does have plant life that uses H2O and photosynthesis.
And, as you can deduce if its poles are as warm as Earth's equator, then the planet does not need to orbit a different spectral type from Earth and can have a fairly similar orbit.
There is still the question of the planet having different plate tectonics but more volcanic gases which was lost from description. The atmosphere should have a very similar amount of nitrogen. I think oxygen would be affected by plant life and the increase in volcanic gases but shouldn't be dramatically high, at least in comparison to the history of Earth.