I agree with most of these changes except for why remove the mention of the emperor
As people who enjoy the prequels they get a nice reference
As for the people who haven’t seen the prequels it adds more back story to Anakin and the emperor
I don’t like the prequels, and I don’t think Luke referring to the Emperor as “Darth Sidious” makes one lick of sense. I don’t even remember him being referred as that in the prequels themselves, only in promotional material like action figures and video games. It’s the only explicit prequel reference, and I’d rather not be reminded of them.
In regards to the Phasma fight, I thought it was another unnecessary prolongation in a film with too many unnecessary scenes. I’d rather Phasma be killed off in TFA than randomly reappear here only to do nothing of consequence. Sure, as Dom (I think) pointed out, it’s important to show Finn fight his literal past, but we got that already, and he does it again 20 minutes later anyway. Phasma is a useless character. I like the idea of their fight being repurposed in a TFA edit (not sure how it could be accomplished, though).