Bad Thoughts wrote:
^Aren't they more like Buck Roger's stargates?
Yes, and like various earlier "jump point" or "gate" drives that had been portrayed in science fiction over the decades. There is virtually nothing that has ever existed in science-fiction film or television that wasn't around in prose SF at least a decade earlier, usually two or three decades earlier.
Why did Starfleet rename it "Deep Space Nine?"
The "Deep Space" designation seemed to be for starbase-type facilities located beyond the Federation's borders. The former Terok Nor was evidently the ninth such station to be established since the usage was inaugurated. It seems to be a successor to the 23rd-century usage which gave us "Deep Space Station K-7" along the Klingon border.