actually apparently there's something in the post game town now that was originally added in the PS3 version that lets you re-do boss fights(and get secret missions if you missed them)
Yeah, that will alleviate some of that.
All Titles is still super easily missed though. That covers things like having all weapons (some weapons are literally sold in a town once, you leave and can't get them again), stuff like that. Vesperia is a minefield of missables.