I seem to be sruck in this place. I have found the key in the maze but I can't seem to find any other keys to open some of these locked doors. Anybody have any idea where to find other keys?

Your question is a little too vague, I think, but here are a couple I can think of:

There is a high-level locked door in one of the Liche's rooms. This can only be opened by a super-advanced thief, a really strong character, or using a key gained from an optional side-quest.

There is a locked door with a face. This doesn't need a key, it needs an item gained from the Liche.

The Liche's door is opened with a key found in the dungeons.

Off the lich? Erk. Now I'm worried - the only item I got off him was his staff (bad). And that doesn't seem to open the door (worse). And I don't think he's coming back from where he's gone (arghh).

Help!

take the staff and use it to open the shrine of anephas.

if you hadn't killed him, he would have given you a key to the dungeon, and if you bring him back a relic he....does something. I'm not there yet, but I knew not to kill him. you just talk to him until he gives you the key and asks you to get a Relic form the dungeons.