About Finn.

Basically, I think Finn should be made into a more selfish character in 7. Three major reasons for this.

He would have more interesting character development.
His motivations would be made clearer by simplifying them.
Watching him grow from a lower point would be much more rewarding for the audience.

This also would require minimal changes.

If possible, don’t have Finn shake his head when he doesn’t help execute the villagers. Finn’s still good at heart, but it is a little on the nose and I think lowering his gun is a stronger action by itself.

When Finn first sees Rey getting mugged, he doesn’t run over to try and help Rey, he just gets up to see what is happening. He’s not a hero at this point.
But when Rey asks if he is a part of the Resistance, he immediately begins playing the role of the “hero” because it could be a ticket off Jakku. He grabs her hand because that’s what he thinks a hero would do, not because he truly cares about Rey or BB-8 at this point in the story. By not painting him as a nice guy before this moment, I believe it could help recontextualize his actions.

Trim Finn’s confession at Maz’s castle. Primarily the line, “I wasn’t going to kill for them.” This makes it sound like his morals were his main motivation, while in this version it was actually self-preservation. You could argue Finn was trying to not make himself sound as bad, but that just make things unclear for the audience, going against the premise of this change.

And those are the main things. These changes also help justify why Finn would kill other Stormtroopers, like when him and Poe are escaping. At this point all he cares about is his own survival, not doing the right thing. So if other Stormtroopers get in the way, so be it. They literally make a joke about Finn’s priorities just before with the “Because it’s the right thing to do/I need a pilot” line. I think Finn’s main goal already in the theatrical film is to run and survive, but these few changes help keep that clear, and toning down his niceness early on makes his overall progression more satisfying.

While it isn’t necessary, I think this is also why cutting Phasma out of the third act would help improve his arc. Phasma and Kylo Ren represent two different things for Finn. When Finn faces Kylo, it represents him facing death (Finn probably associates death with Kylo Ren, and he even looks like the grim reaper) to protect someone other than himself.

So when Finn faces Phasma in 8, she should represent whatever he overcomes in that film. The dilemma of choosing a side, basically. And I think Phasma is a good symbol for that.

That’s why I think Phasma shouldn’t even be in the third act of TFA. Finn “beating” Phasma at that point sort of takes the wind out of the purpose of their confrontation in 8.

At the VERY LEAST, one could do sort of what I think darthrush is going to do in his TFA cut and really deemphasize Finn’s celebratory attitude while they have Phasma at gunpoint, so cutting their conversation together “I’m in charge now!”, and maybe “Yeah, there is”, Finn grinning, after the trash compactor line.

I think similar changes can be made to 8 as well, like adding back most of his deleted scenes to clarify his motivations, like Hal is planning to do. Make Finn seem less eager to help the Resistance after he gets caught (maybe things like cutting, “If I can get on that ship…” and maybe don’t have Finn interrupt Rose when they’re telling Poe the plan).

Honestly these are mostly small trims, but I think they would go a long way to help clear up Finn’s motivations in both 7 and 8.