This is a good topic, thanks! Gotta cut this in parts:
I would completely cut out the succession plot. It's unnecessary, we don't have any real business there (outside the memes about installing a puppet government), and it doesn't do anything for the world at large. And for a "low-stakes adventure" it's actually too serious. So keep it out; let them solve their own politics.
Meanwhile, we actually go to explore and have adventures with a select small group of people who have a reason to be there/with us. And let us start by doing only the things that we are there for. And I'd include factors that were specifically set up or promised before. For example:
Us: We want to go back to adventuring for a bit to relax and have fun and see the world, be Azem and play tourist and solve people's problems in fun and unconventional ways that are our idea. Give our character the initiative of the person that jumped into a volcano. Let us make a difference by merit of being us, regardless of powerlevels. And also we've just been set up as wanting to see the cities of gold, so let us see the cities of gold and make them something suitably cool and fun to explore. This was a travel recommendation by someone who knows us, and whoever picks up the MSQ writing has to account for that.
Krile: Also wants to see the cities of gold, wants to find out about her background, wants to go on an adventure with us, and especially and emphatically wants to fight and be useful in battle situations with us. That's been her big gripe all this time. Let her do that. Give her a proper training arc that deserves its name. We don't need a new character for that, give that to Krile, let us teach her and explore the world together and have fun.
Erenville: Is a cool guy I want around, and I love adventuring with him for the 5 minutes that we got on our own. He can have the New World backstory he got here or not, and he can have the goal of also finding the city or not; coming from Endwalker they could have taken that in various directions, but if we're going with it, have him also be motivated, and maybe want to see his mom on a detour, and we oblige him early on because that's what friends and decent people do. Whether it goes well or not can go either way, depending on what the plot needs, but let us earnestly attempt to go along with him in a timely fashion.