I don’t think the Nari scene is necessary, since it’s main point is to show that Kenobi himself has fallen into depression and has become jaded about everything, willing to abandon his moral conscience out of cowardice borne of his PTSD, which doesn’t seem to be as much at the forefront of this edit. This Obi-Wan is more practical, I feel, but driven by his sense of duty more than anything. There’s hints of his having become unbalanced (his inability to communicate with Qui-Gon, for example), but that’s more of a side thing than the main point.
The only other useful thing about that scene is setting the idea up about Obi-Wan burying his sabers in the sand, but I don’t think it’s that big of a stretch to just cut to him retrieving them once he’s resolved to leave like in the edit.
Really, Nari as a character was so mishandled because they decided to show us him through the Inquisitors’ POV rather than his own. If there was a scene of him heading to Tatooine or giving any explanation of the journey he’d been on since Order 66, I’d probably feel better about leaving it in since it’d be set up better. As is, I think his appearance only really works in this context via the Inquisitor scene in the cantina.
I didn’t interpret it that way at all. He’s depressed and jaded but he’s absolutely right to keep his head down and recommend other Jedi do the same. By not going around calling himself Obi Wan and making a big show out of things he’s protecting Luke, which is the most important thing he can do. And his advice was right, Nari just got himself killed anyway. Everything he said was true. And again when he tells Bail Organa that his primary responsibility is Luke, that’s also true.
The show later undercuts this by trying to make it seem like Obi Wan is supposed to abandon Luke so he can have more off world adventures (maybe in season 2) and his “flaw” was not being adventurous enough (?). I hate that but it doesn’t have to be that way. The opening is pretty good and doesn’t have to set up that non-arc.
It’s important to remember that this is not The Last Jedi Luke. With TLJ Luke there is no purpose to it, he hates the Jedi and wants nothing to do with the story. Obi Wan, inside this show or not, depressed or not, is being an isolated hermit for a very good reason. He has a purpose and he’s still a Jedi. There’s a plan in place.