there's no manual ingame, and a search didn't come up with this, but...

I'm in the thieve's guild...but I cannot pick pockets? I don't see any "Pick pockets" option or anything in the character dialog, whether I am sneaking or not when I initiate it.

And attacking the target just gets me in trouble of course.

So how am I supposed to get the dang key off Sovor Trandel (I just bought the dang diamond for the first job...)

You must be sneaking, then just activate the NPC (as though you are trying to talk to them.)
Then you can see their inventory.
I don't understand why that is not working for you.

You don't have to pickpocket the key from Sovor... if he really likes you he will give it to you if you ask him the right question. In Morrowind, there's often more than one way to complete a mission.

(and you didn't have to buy the diamond either... you could have stolen one. you are a thief after all)

Whups...I had been holding down the wrong key...key's not in his inventory though.

And stealing a diamond wasn't an option, there is a guard standing right there, I'd never make it out the door.

There might be things in an NPC's inventory that you don't see every time you try to pickpocket this NPC. Try again and see if the key appears there this time.

Also, stealing is an option even if there are NPCs around. Just make sure your sneak icon is visible when you try it.

I gather that your sneak skill isn't very high since you can't see the whole inventories and can't steal if someone's near. Get training or just... sneak.

I figured that might be the problem...wish there was an "always sneak" hotkey option like there is for "always run"...heh.

Morrowind Code Patch (MCP) takes care of that. PC only, though.