Ok im really confused about this. Is the space thing we have now going away to be replaced by this new space war thing? Or is it something entirely new and we keep the space thing we have now? Also do we have to pay for this expansion? It says early access the 3rd but doesn't say how we get in?
It's separate. The existing space remains; however, any character can do the new space, starting from level 1 (and it rewards XP).
The expansion is free; however, subscribers get access on December 3rd, where as premium players get access in January and free players in February.
There are optional cartel coin purchases you can make for particular cosmetic ships, or to speed up earning access to other ship variants. Note, however, that all ships start out "equal" (though different). You upgrade them by earning "ship requisition" which you can only get by playing (you cannot buy ship requisition).