From my memory, the misable stuff isn’t the important, but it is frustrating to not be able to get. I would say if you aren’t worried about missing a few unlocks, just accept that you’ll miss stuff and don’t stress about it.

If you’re the type of person (like me) who finds out they missed something and feel compelled to restart, even if you were never planning on 100% the game, then yeah, use a guide. I wouldn’t use a guide for everything, but I’m certain there are guides that say when misable stuff is coming and how to get them.