None of the leaked designs look quite related to Trek to me, which is fine; if the style is more baroque space opera well I'm very fond of that sort of thing and, anyway, I somewhat doubt a Klingon Sarcophagus Ship is going to be the central location for the series (but then again, there was a show set seven years on a Cardassian mining facility, so who knows.)
With the Klingon ship being labeled as a "sarcophagus ship", I suspect, if these are legit, that this is an ancient ship that's being discovered in-universe in the "present" of whatever era the show is being set in. I'd be surprised if it's indicative how the present-day Klingon ships would look like.
This is what I'd suspect too. In fact, I have a theory: Sarcophagus suggests it's some kind of tomb, but the name 'sarcophagus' recalls nothing so strongly as, well, the Pharaohs of Ancient Egypt to me. What if it's a tomb of a Klingon Emperor (or more than one)? We know
very little about the various imperial dynasties in Klingon history, other than them ending around a century after the Klingons got warp drive (and if not a warp ship, this could be a pre-warp tomb drifting in space.)
It could also somehow be a tomb for Kahless; which may not quite fit existing lore about Kahless but given how obviously mythological that is there could be a pretty easy explanation for that.
There was talk that one of the reasons Robert Duncan McNeill's character on Voyager was Tom Paris instead of Nick Locarno was because they didn't want to have to pay royalties to the writer of First Duty for every episode of Voyager. They'd likely have to pay similar royalties for using the Hur'q.
There's certainly been talk of that (there's also been talk that the changed the character because the backstory for Tom Paris is slightly more sympathetic than Nick Locarno - Paris took the Wesley Crusher route of owning up to his mistake); I don't know if they have to pay royalties for the use of alien species because if they do they've been pretty comfortable with doing it already - Maurice Hurley came up with the Borg, and multiple episodes not penned by Hurley (who only wrote "Q Who?" of the Borg episodes) as well as an entire regular character on Star Trek: Voyager stemmed directly from his idea.
Whether or not they should use the Hur'q; I doubt there's any real obstacles to them using them.
But JJ Abrams apparently has a boner for blowing up planets, he did it twice in Trek09 and god-how-many-times in Force Awakens.
It's interesting to me that he blew up two planets that are fairly important in Star Trek's lore in his Star Trek film, and in Star Wars blew up a planet invented specifically for the movie which, however, bore more than a passing resemblance to another better known planet in the Star Wars continuity, Coruscant. I wonder if Abrams had wanted to blow up Coruscant, but was vetoed by Kathleen Kennedy. But I think I digress.