I gotta admit, I dropped a few quests entirely simply because of the boss fights were insane; Jean's final (?) route boss is absolute bull if she manages to drop either your casters or melee specialists out-of-order with her party-wide attacks, and I can't even beat Greg's second coming since he just tops himself up before launching another ten or so attacks on my party *per turn*, completely wiping my caster line before they even get a turn to act, and they're all sporting at least Mithril-level gear and (hopefully) reasonable class lists. And I'm not even looking to trying to finish Kuro's quest after getting soundly beaten by the previous two boss encounters. And as someone already mentioned, a dodge build rogue is just mincemeat since the AI gets insane to-hit bonuses.
Not sure if there's any way to beef up to sufficient XP (roughly 3k for main) or power levels anymore since advancement of stats is now land-locked to turning in slavery missions, which yield only so many tokens that can be used to buff your mainliners, but never enough for the whole party, leaving their leveling sub-par while trying to turn in quests.