you are going to have problems in Part 2 with that party I think. Only one of your characters can use the Ether Weapons (found later on in the Fortres of Anarchy - Alamos Dungeon Map - and only accesible through the Hive) and there are hordes of monsters in Part 2 with special attacks ranging from drain Mana, drain HP, disease, curse, dispel magic, etc. etc. You should have at leaast 2 (3 is better) fighter class characters in your party. I generally play with Warrior, Paladin, Priest, Archer but of course, each to his own.In answer to your question about the fountain of magic. It is somewhere in Kastutia (Bootleg Bay), I don't think you will find it hard to locate it. 
The Lair of Kochei was designed for a level 70-80 party armed with very strong weapons. The Ice Weapons of the Gods that are in the Fortress of the Ancients (Castle Kriespire) will work nicely for this.
I have NEVER played TCC (even in Alpha/Beta playtesting) in any mode other than Adventurer. MMF is not on my wish list of things to do (I play these games for fun, if I want a job I'll go out and find one). Oh, and before I forget, to get to the Ice Weapons in MMF there are lots and lots of Diamond Golems (1000 HP and a very high AC, and they attack with Drain HP 100%). Lotsa Luck there. Just one of those Diamonds can take out an entire party with 4 hits.
