I read about this one on Ed Gorman's blog, so I figured I'd read it. If you're familiar with Carter, you know that a lot of what he wrote was a pastiche of something or other. In Star Rogue he seems to be channeling Doc Smith, or some other author of slam-bang space opera.
Saul Everest is humanity's only immortal. He doesn't know how he became immortal, but it doesn't really matter. He also has a Star class mind, and of course his telepathic powers are developed to their highest point. Mostly he lives an idle life in retirement from Citadel, a cabal of superminds and telepaths that manipulates the flow of history while remaining in the shadows.
Saul is jolted out of his retirement by the report of a mysterious object, perhaps a rogue star, that's appeared out on the Rim. This object is merely an excuse for Saul to leave his comfortable retreat and have all kinds of adventures, which, when you think about them, aren't really all that unusual or extraordinary, at least compared to other space opera that you may have read. There's plenty of action, though, and things zip right along.
As always with Carter, there were various sequels and prequels planned. He tells about them in an "Author's Note" at the end. I have no idea if any of them were published, and I doubt I'll be reading them if they were. Star Rogue was fun and a nice little diversion, but it didn't make me want to seek out anything further in the series.