Q:

How would gravity affect a torus-shaped planet?

My planet is a Super Earth about twice the mass of Earth. I'm not asking how it formed, although that would be nice to know. I mostly just want to know how long it would stay a torus shape, and how it would affect other other objects(including life on the surface, if habitable).

A:

It can't exist and it can't support life.
Such a thing would have to be constructed in space.  It would not produce any gravity unless it was spinning, and then only on the inside.  With just rock holding it together, it would quickly fly apart and break up into asteroids floating in space.  Then, over a few million years, they would crash back into each other and begin to form a proper planet.
For any of this to work, you would need magic, or it would have to be artificial.

