Too many posts to quote, so I won't quote anyone, just some clarifications in random order:
- There's NO third person view whatsoever. You can set an external camera behind the ship while you're flying and that's it. While on foot, you're always in first person, period. Those screenshots where you see a pilot in the cockpit from the back, are so because the player was standing there while a npc was piloting the ship.
- X Rebirth was the same, and always had a cockpit. Always, from the very start, as far back as an Alpha. There never was any public beta, and in any case that first cockpit had been there from day 0. In time, years after release, they added three additional cockpits, and finally even some kind of loosely playable external view of the ship from the back.
- X Rebirth had never been a failed console port, how this is still going around is beyond me. The initial focus on pad controls was mainly because of Steam Big Picture and admittedly a huge mistake. If anything, they tried multiple times to bring their titles on consoles, always failing due to the stricter hardware limitations among other things. Surely NOT the other way around.
- X3 didn't have any cockpit. Someone in time modded some from X2 back in X3, there were probably also a few totally new one, but always available as mods. The vanilla game was just a camera in space, for every ship.
As for X4 requirements, I can say for sure one of the developers works on a i7-4770 with a GTX 970, so if he can develop the game on that, you'll probably play the game on that. Actually, it will probably play on far less than that, if you are willing to find some compromises.
Mind that whatever the hardware, it's still an X game: there's no controlled environment for which to optimize performance beyond a certain limit. Give the game enough stuff to calculate (ships, stations, complexes, fleets, huge multi-sector empires), and it will tax everything and anything you throw at it.