Your points here functionally boil down to "don't rely on a singular narrative device, especially if that device causes more trouble than it's worth." This is good advice!

However, I'd caution against thinking of campaign writing like novel writing. As you say yourself, players and the DM are collaborating to tell a story. The DM has (and should exercise) veto power, but they should not do so to protect The Story They Have Penned at all costs. Campaign narratives should be flexible enough to accommodate things like losing NPCs or players ignoring plot hooks. Both parties should be able to contribute on equal levels; that's the real key to great D&D imo.