1 and 3 are both great, and I'll go against the grain and say that 4 is pretty mediocre.
James Bond, for instance, is a different person from each actor to have played him
That's not canonical, merely a popular theory.
The idea of being able to essentially species change a Klingon into a Human with TOS-era Klingon medical tech sounds impossibly advanced for what the Klingons are known for.
It's also something that literally happened in a TOS episode that almost everyone saw and liked.
It's one thing to do as a one-off gag or a nostalgia bit. It would not have been possible to take seriously for an ongoing series in 2017, except for hardcore fans that don't need to be sold on it.
Irrelevant to the transporter as the same matter is moved by the matter stream and reassembled in the same order. This is less asking if the ship of Theseus is the same ship after the hull and the mast were replaced and more asking if my kitchen table is still the same after I took the leaf out, folded the legs in, put it in a truck, moved to a new house, and set it back up
So things may move pretty fast with Korby. A whirlwind rebound after things get awkward with Spock?
Structural differences in their larynx, tongue, or lips seem likely.
I must say I'm already a big fan of Pelia.
As always, I feel compelled to point out that Turkana IV was never said to have been a member of the Federation - they “severed relations” with the Federation, but that doesn’t necessarily mean they were a member (in fact, I think it strongly suggests that they were not, as that’s a very clunky way to refer to secession).
That's a reasonable objection to raise but I'd counter with the point that it seems unlikely that a human colony could be established except under the auspices of the Federation, or at least United Earth.
You know, as a big FF8 booster, this makes me reconsider some stuff.