@Anband11 No, I'ts just that the goal of this experiment is to observe how small partles are attracted to eachother and over large scales of time, end up becoming giant compounds of molecules we call planets.
You can move a particle if you want, but it "messes with the natural order of things", or what I also Like to call "interference by god". Since they only things that affect matter is other matter, and no other "external" forces created from outside of the universe, if such thing existed...
You can change anything you want before you run the simulation, but in order to see the true results, using the edit tools to alter the position, motion, or energy of the objects after the simulation was ran is not recommended.