Can you use isolate/separate to move mobs?
Nope. Tried it - you get a message that tells you no. *sigh*

Do you have to know the grapple skill for separate to attempt a grapple?
Yes. Grapple was awesome on Jesp - you can start a fight with it, if I remember right, but you do have to be barehanded. It's a great way to get nice weapons that aren't nodisarm, or remove weapons that you aren't familiar with.

Is stench cloud targeted or is it like a faerie fog ability?
Never tried.

Can you bribe constructs?
Never tried

How many licks to the center of a thief pop?
Look...if you wanna mudsexxor, you're gonna have to work harder than that...ask me in char, sheesh.