twin paradox appears and is solvable with only special relativity, gravitational time dialation requires general relativity.

No, if both persons are in inertial frames of reference the situation is completely symmetric so the 'paradox' does not occur. Also note that it is not really a paradox because general relativity has a conclusive answer to what happens to the twins.

It is; however, not possible to set up a twin paradox-like situation with neither twin never leaving an inertial frame. This is because if they want to move apart, and come back again, they need to accelerate somehow, and the act of acceleration causes you to leave an inertial frame.

He has his mother and father. In The Time Paradox, he has two twin baby brothers.

The twin paradox is a thought experiment in special relativity that involves one twin traveling at high speeds and the other twin staying on Earth. The twin who travels at high speeds will age more slowly relative to the twin who stays on Earth. However, this does not directly affect human metabolism as it primarily involves differences in time dilation and perception of time. Metabolism is a biological process that is influenced by a variety of factors such as diet, exercise, genetics, and overall health, rather than the effects of relative motion and time dilation.

paradox = paradoha (however, the English word "paradox" is more common).