I'm not a developer, no. I simply prefer to explore all the available content at once, so I generally play games while reading their code in parallel, looking for strange requirements.
Sometimes I come across cool easter eggs, sometimes I get confirmation that the game isn't behaving as expected.
And when the platform used is as open as renpy, it's easy to find information to make a quick fix.
Books are generated every morning using the generate_books() function, which defines a table with the books found in the academy, another with the campus, then chooses randomly three books in the academy and one in the campus. You will
not find the books at the same places than in another gameplay. You can find four per day (if you fix the cafe), but while it's always good to have some in reserve it's not mandatory (100 are required for a quest with Amelie in a later season and the rest can be used for points or sold later to upgrade spells).
Note also that while Ahchi's Gameplays are a nice gesture from him, the versions played are not the last available. So as he mentioned there will be changes.
For Lustagram, it only provides some nice photos, and some choices provide answers that add a bit of depth, but there's nothing more associated in the code. I played my games leaving this aside and only opening it at the end.
NeoStarr Assuming you're using the latest version available for PC, peeping should display a few attempts before offering the same choices each day (attempts that are unlocked after trying the previous one). However, I can't find "enough for tonight" in the code, is that the exact text displayed ? Are you using mods ?
If it's just to create a save to transfer to season 2, these choices are not transferred so you may skip this.