I was curious if our solar system would look different in a few billion years, but I found in a few thousand years the inner planets are thrown into the coldness of the void. I'm not an astrophysicist but I'm confident this will not happen
Does increasing the frame speed dramatically cause the physics to misbehave?
Yep, if you set the frame speed too high, the orbits will become unstable. Also, the position of the planets won't look any different (unless we, or some other species, mess with the orbits), but the sun will be brighter and on its way towards becoming a red giant.