Creating a Dyson Sphere would be an absurd challenge. But the Death Star isn’t a normal Dyson Sphere. Instead of containing a natural star which serves as a source of power, the Death Star has some nebulous artificial power core, with an energy output several times that of a main phase star.

This is flatly impossible, and is going to be impossible for a very, very long time. It is absurdly, staggeringly, and utterly impossible. We’d have to have the technology to not only move planets worth of matter throughout a solar system, but we’d also have to have the technology to create an artificial star. What.

By the standards of, say, the Roman Imperial cult, somebody who acted like a ‘fan’(loved his fandom, participated in the rituals at Augustuscon, etc.) would probably count as a good pious sort of guy. 

By the standards of a more rigidly orthodox religion(Calvinism, say), a ‘fan’ who is gung-ho about Star Wars; but doesn’t actually believe in the literal truth of a galaxy far far away would be in trouble.

Even in theory and overwhelmingly in practice, religions differ in how much they demand a specific internal belief state(something that fandom followers would generally fail), vs. how much they are content to ignore your internal faith state so long as you affirm the correct sources and reject the correct sources(something that fandom would be very polarized about: some fans are excellent at rigorous canon/non-canon nitpicking and love nothing more, while the fanfic enthusiasts would probably be seen as akin to the dangerous loose cannons, nuns having visions, non-sanctioned ‘holy men’ and various others who usually end up being either suppressed or turned into official saints)vs. how much they really just want you to observe certain rituals in certain social contexts and leave the believing to the professionals(which ‘fans’ would probably be pretty good at, since they tend to like Cons and such; but mostly don’t affirm the actual truth of the object of their enthusiasm under questioning).

http://m.gizmodo.com/5146010/death-star-costs-156-septillion-14-trillion-times-the-us-debt

But fictional worlds can certainly turn into religions. Scientology is a religion based on the bad SF novels of a bad writer who was an unscrupulous confidence trickster. The pagan religion of Ancient Rome and Greece comes from the poems of Homer and his fellow entertainers.

Carney will certainly be asked about it and have a response. And the response is an opportunity to get an administration message through. Like pointing out that defense costs have to be considered against the likelihood of a threat and the likelihood that the proposed weapons system would be effective against that threat.

The only possible way this particular one might rise above the ‘here, have a nice soothing form letter’ school is if somebody decides that a sufficiently cute pop culture reference joke response will poll incrementally better than a form letter.