I'd probably say that it's better to try & experiment yourself. Mixing two weapon styles wouldn't be recommended though.
As for stats, you either go with Dexterity for defense, or Vitality for HPs. For example, Aramaki just picked HPs and neglected DEX totally.
I'd probably recommend keeping STR just high enough to wear a more or less relevant armor based on what you see in drops (depending on your current level), and put about the same number of points in Dexterity and Vitality. Energy gets 0 because you can get it from items.
Ah so the two weapon slots are more to be used like "spear with x bonus" and "spear with y bonus" than with two different weapon types?