Save the game position to disk regularly, especially before dangerous moves and after a tough portion of the game. If your champion has not enough MANA to chant a spell in total, chant as many syllables as possible and then sleep. When he or she awakens, the remainder of the spell may be chanted. Each champion may pre-chant a spell and keep it at the ready in case of encounters in some surprising situations. You should also know by now that in order to use an object or a weapon, that it must be placed in right hand. Best use of chests is to store one type of item together in each chest (e.g. food in one, clothing and armor in another, etc).

Go to the dungeon entrance and face the door. Cast the spell "OH EW RA". You will see someone interesting.

To advance ninjas a level, stand in a hall and throw your weapons. Then get them, and repeat. This also works with magic and fighter levels. Cast a spell at the air, or slash and bash until you gain a level.

Halk isn't as stupid as you think, give him magic objects and he will gain enough spell points to cast "LO". Have him keep casting this and his magic powers will develop.