LUK adds avoid for any class, INT adds MP for any class. STR adds weapon def to any class and DEX adds accuracy to any class. As Hero (and any other warrior) you want to keep your base dex as low as possible and still be able to hit monsters 100% so you can maximize your dmg output by having higher str. Here's a nice accuracy calculator: http://screamingstatue.com/accuracymain.php Luk and int are both not needed for warrior. STR does not add more HP/MP, only INT adds MP.
Luk also adds accuracy, int adds magic defense, and dexterity also adds avoidability. Had no idea about str adding wep def lol.