For the First Problem you are best Using magic to pull him into his own traps and then use one character to navigate the traps. the seccond set is more difficult. Easiest way to do it is to send your strongest party member through the least painfull route and accept the little damage. Rememebr you only have to get one Party member through it alive.
BTW the best web site on gods green earth for this game is
http://www.hi.is/~eybjorn/krondor/krondor.html