So first of all. Procedural and a changing universe.
Of course this would be possible on a single pc. You don't need to simulate every pc. You use a scaled simulation, depending on the players position. So for example, the system the player is in, simulates all NPCs directly. Physics, etc. only by NPCs near the player. Then the near system is simulated with only NPC states. Number of NPC ships, factions, position, type of the NPC ships and possible aswell the skills of them. So the data could let other ships jump inside from there. In systems more far away, you only simulate the faction data and their strength. Many large gameworlds in single player games act like this.
For the hacks:
No offline character upload in the online universe, offline data and character stored locally, online data and character stored on the server.
And again some datas could be randomized (location of value sides, etc.) and the market datas would most likely be online in the first month of the game.
For the game changes and the dynamic universe, that could be possible done with some randomization. Being identical with the online version is at least for me not nessesary. Optional in an more connected mode would be okay.
Doesn't have to come out on the first days, even when an offline mode would be done some month after the release would be okay.