I mean, it was telegraphed in S1 but there are definitely going to be some Gorn retcons this season.
I'm fine with this! But it was already tough to reconcile what we saw in S1 with later crews, "attending Gorn weddings" (much harder, imo, than the more reasonable 'they have been encountered, just in a limited capacity and with few survivors) and a full on invasion plotline - featuring Spock and Uhura no less - makes Arena tough to reconcile.
Again, that's fine!
I like the current Klingon design, though I wish they had kept the double nostril from DIS. The redesign went too far but their attempt to physically show the Klingon's redundant biology was appreciated.
The actual episode's plot was...fine. A bit rushed. Felt like a Mass Effect sidequest which is fine for an ep but hopefully not the feeling of the season as a whole. Establishing the character's war experiences and generally situating the series as post-war is probably necessary for the rest of the season. I have to wonder if they went out of their way to only show Spock and Pelia with the Klingons given other crew.....probably aren't ready to split a barrel of bloodwine.
Speaking of Pelia: a race of immortals living in secret alongside humanity and now just regular, serving members of Starfleet? Identifiable by accent even? It's a BIG swing and probably the most interesting (though for now unexplored) idea in the episode.
On the Crossfield refit...presumably from the 'shell' style associated with the pre-TOS ships (as seen in DIS Binary Stars sequence) with the Enterprise's modernized plating? Probably would have been simpler to just have a new class.
Not to mention it seems generally pretty dark to suggest that Federation officers were regularly taking performance enhancers during the war...