Oh, dear
I will try to answer in parts, there are things that seen quickly seem illogical, but I want to give my point of view of why some things are done the way they are done.
The game is intended to be open world, with freedom and where the characters "move" with the player, not just wait in one place forever to continue a linear story. In fact, the story unfolds in several lanes, some lanes are bifurcated (Mary/Maxy), others have ramifications as a consequence of others and so on. Each lane, in addition, has a main story "Necessary to reach one of the endings when the game is complete" and secondary content "Everything else", this to show the characters in other different contexts, and not just as a puppet waiting to continue an immovable script/plot.
If you see the message "Main story completed", it means that the main story content was completed, but it does not mean that there are no secondary things to do (If u wish). Also, depending on the context, sometimes there are characters that lead you to circumstances (something usual in Maxy or Sasha) and others that are more passive to your interaction with them (Prim for example), this is part of their personality too.
Sometimes other things are happening in Argleton, even though you don't know about them (like things with the Dragons in the Shogukuni),are things that are foreign to you, but that at a given moment connect with what you do.
My intention with this, was to give movement to the world and the characters, a feeling that the town is alive with people doing things, although you are not directly involved (That's why it's a first person game, there is no omniscient narrator that jumps from one point of view to another, he is fixed and doesn't know everything).
However, in the profiles there are details of each main activity and all secondary activities for each character. I have been improving this, to guide the player more, with the new Gallery telling you what to do for a particular scene on the next update.
It's a game to take it slow, sometimes let yourself go and enjoy Argleton. If you go into marathon mode with the "I want to unlock as much as possible right now" mentality, well... Its not the intention... I know this is usual in other sandboxes, but I wanted it to be different here.
As for the grind, this is something that has been evolving quite a bit in development, and the Lucky Paradox community is always trying to give suggestions and I try to balance all. However, history does not require attributes or grind, is just for side activities.
Anyway, raising attributes will be easier and easier, because there are still features to be added
Still, you can manage, automating the attribute gain with Books and the Fitness gain with the weights thanks to Kaede.
The Appeal, for now it is a useless attribute and I must do a rework of it, but it is thought as a "Bonus", not as a necessity (and to represent when you sweat, and you are dirty or clean xD, as a detail too, I like these small details on games).
The high fitness requirement to climb the Shogukuni is not random, it is the ultimate test that a Dragon must perform (although they do it by carrying a huge rock), if the requirement is silly, it would be breaking with that aspect of the story. Nor will it cut content, since it is more a detail that gives strength to the World Building of Argleton (You talk to Johan and nothing more).
The Maxy/Mary bug is still not clear to me, I've been trying to replicate the error, but it doesn't happen to me and reviewing the code I can't see anything wrong either x.x
Oh shit! this post is getting very long, and I don't know if you will read all this, lol