Speed is how often your attacks hit. Luck is the Critical Hit percentage. Haar is an axe-weilding Dragon-Knight. Zihark is a Trueblade, or powerful sword guy. Mia is a Swordmaster, less powerful sword guy. Micaiah is a weak magic pussy. If she dies, you lose. Rhys is a Bishop, or healer.
FFTA has so much untapped potential. The combat system is so great (although they desperately need to speed it up) and yet the games are always amazingly dull...