This isn't a thread for spoilers, but some of the "inconsistency" of Kerrigan from Brood War to this concerning Mengsk can simply be explained that she's not the Queen of Blades anymore.
No idea if she reverts, just addressing that one point.
Raynor is more..broken..in his change, but due to how long it's been and all the new people playing, regressing and then repeating the Brood War arc for him over all three games wouldn't be surprising,
It's kind of like how at the end of WoL, people were like KERRIGAN WAS RESCUED? WTF.
If they meant for her to stay like that, they wouldn't have done it at the end of game one.
(Again, speculation, but come on, it's not how you write love stories, they don't get back together at the end of book one).