Three questions:
- Is it possible to dynamically change a planet's size and mass? Texture? Position?
- Can an MFD change the position and orientation of a vessel directly? (the answer is probably yes)
- If so, is it possible to implement "seamless" interstellar travel by keeping the planets the same, but changing all their parameters and positions so it is as if you arrived in a different star system? Even if you can't move the star, you can emulate moving it by moving the vessel instead; after all, only relative positions and velocities are physically meaningful.