I started reading Picard: Last Best Hope. I'm trying very hard to keep the Novelverse timeline separate from this. My question though is, when does Worf become First Officer on the Enterprise? He became the Ambassador for the Federation/Klingons at the end of DS9. In Nemesis he was traveling with the Enterprise crew from Riker and Troi's wedding to Betazed for the second ceremony....but it was my understanding his status hadn't changed?
While Nemesis never clarifies why Worf is back in uniform, there was a deleted line to the effect that he'd not found himself suited for the life of a diplomat. Given that Worf is the one that tells Picard that they've finished repairs and are ready to turn the ship back on at the end of the movie, it's reasonable to assume he was back on the ship permanently even without the explicit line saying he was no longer an ambassador.
In Nemesis I don’t think it’s explained what led to Worf’s current status. He’s just at his regular post. It could be assumed in the reset canon timeline that Worf just bacame the first officer right after Riker left in Nemesis. His move from ambassador to the Enterprise would be untold at this point, unless whatever temporal shenanigans that result in this reset canon timeline leave the A Time To novels in place for the Litverse moving forward.
As I've said before, at this point there's no reason to assume anything in the novelverse pre-2380 has to be considered invalid. The novel continuity has adapted to new canon before, when ENT was on the air, in much the same way Star Wars tie-ins did during the Prequel Trilogy -- not by throwing the whole thing out, but by setting aside the specific parts that were contradicted and carrying forward or adapting the rest to fit the new continuity. Of course, the bits that had to be disregarded then were much smaller -- The Sundered's description of Tholian anatomy, Andor: Paradigm's description of Andor as a temperate planet rather than an icy moon, that sort of thing -- but the same basic principle could still apply now, or at least I haven't heard differently.
Surely being First Officer of the Enterprise would require a lot of diplomatic skills. Also due to the events of "Change of Heart" he'd likely never have a command of his own.
Surely it would. But obviously not as much as being an actual diplomat. Just like a science officer has to be skilled enough to fire a hand phaser but won't need to be as skilled as a tactical/security officer.
That was just one officer's opinion, spoken in the heat of the moment, during wartime. Worf served admirably for the rest of the war, became a Federation diplomat, and eventually was welcomed back into Starfleet. That's a lot of life experience and work experience. Just because Sisko thought Worf would never move up doesn't make it holy writ.
After the Dominion War, that black mark on his record, which was more political than anything, probably wouldn't matter any longer.
Hell, even Sisko added the qualifier of “probably.” That Worf “probably” wouldn’t be offered a command of his own. Which even then didn’t rule it out as a possibility. Not a likely one, but even Sisko was not saying it as a certainty.
Letting a valuable intelligence asset be killed by the enemy in the time of war, when the information they could've provided might've saved thousands of lives and allowed for a speedier victory for the Federation and her allies, add to that his firing on an unarmed civilian transport, granted that was proven to be a ploy by the Klingons to discredit him, but still it shows a pattern of behaviour that would probably make many at Headquarters wary about giving him the fourth pip. If he did ever gain the rank, I can't see it being of a modern ship of the line, but rather something relegated to milk runs--maybe once he'd had no major incidents, enquiries or trials regarding his decision making then he might get moved up to an Excelsior-Class. That's how I'd see things, but he would have Picard singing his praises so all his past mistakes would probably be expunged and he'd be at the top of the list to take over the E-E from Picard. Though I think that a once high profile officer having to scrape the bottom of the barrel for a time would be a fare more interesting story for him.
I think Worf being made Federation ambassador to the Klingons at the end of DS9 counters the idea that the Federation saw him as spoiled goods. Further, we don't know how much influence Chancellor Martok plays in Worf's career as diplomat or when/why he's back in Starfleet (ignoring what Trek lit. has established here, and going by what we have seen on screen or have yet to see). Starfleet is a very forgiving organization. Heck, they left Picard in command of the flagship after Wolf 359. I think Worf's decision in "Change of Heart" would be weighed against all the good things he did before and after that decision and, perhaps with a desire to keep Martok friendly, Worf could become first officer and then Enterprise captain. I think Worf being Enterprise captain would be good because he knows the vessel and the crew and they trust him, it might please Martok, Picard and Riker would be advocates as well, but also it would be good symbolism and perhaps good politics, that a Klingon is the captain of the Federation's flagship. The redemption story you described for what could happen to Worf has been happening on DISCO with Michael Burnham. Personally I would rather see Worf as captain of the Enterprise because he deserves it. And I think his command style would be interesting. I would be interested to see how much he has learned from Picard, Sisko, Martok, and Riker.
I beat this drum more thoroughly in the piece I did on "Rules of Engagement" for my DS9 Rewatch, but Worf didn't do a damn thing wrong in that episode, and that entire story was absolute total nonsense.
There's a comic book where Ezri visits Worf and he's realizing that he's running away from Dax rather than accepting a job he really wants. I liked that take on it.