Hello,
I tried to recreate our Solar system realisticaly, but encountered these problems:
1) I placed Sagittarius A* in the 0,0,0 coordinates and put Sun in orbit in the proper distance and set the proper speed. But the Sun just flew away (it wasn't capable to remain in orbit with real velocity in the real distance from its parent). So I started from the beginning and kept the velocity the program set automatically.
2) I placed the planets around the Sun and started with moons. The inner planets were OK (just three moons anyways), but Jupiter was problem again. Prograde moons didn't cause any trouble, but retrograde moons attached themselves to the Sun, as soon as I changed the direction of their movement (which I did by setting negative speed).
3) Such complex work can't be done in one go. So I saved the simulation, but when I loaded it later, it was running, it wasn't paused, as it was during saving. That caused some more slight trouble, but nothing serious. But when I wanted to launch the simulation, it wasn't possible. It looked like it was running in real time - like 1 sec her is 1sec in the simulation. I wasn't able to adjust the time in any way.