Ribannah's explanation to the classes/skill tree. Only three pure classes - Knight, Cleric and Sorc - and all others being mix of neighbors.
http://www.castlegobs.nl/MM7/suggestions.html
I do not think the six more classes are necessary, but for the existing nine her scheme is quite good.As for versatility of your parties, Zedd, I don't think that strightforward approach (casting GM prot from magic and wacking everybody in the Maze) is only possible. Playing Rev1, I cleaned out Maze vith lvl 1 KTCS party without GM body. It is suposed to be a RPG, not a hack-n-slash game. If Sorc can slow the enemy, while others are firing their arrows, this is a good reason to master Earth magic; if Haste potions are reducing recovery time, it is good reason for putting skillpoints in Alchemie and your Pal's armsmaster skill becomes unnecessary. Personally I like things as they are; it is much more interesting to hunt down tigers, if you are a rabbit. Not to hunt rabbits, being a tiger.