well I would drop the slayer to be honest. sure he can hit hard, but he dies pretty fast too in my experience... or let's say my regular opponents experience
Max out the unit of bile thralls to 10 (purge is pretty brutal against infantry masses ). And try to get one more chicken. Arc nodes are the lich best friend, and the more you have, the easier you can set up the kill.
I don't really see the use of mechanithralls in this list, they can wreck a warjack up good, but if the opponent has a ranged unit (like khadoran widowmakers or cygnarian longgunners), they'll be gone pretty fast.
Skarlock is good, and the two pistolwraiths are almost a must with the lich.
Gorman.. I'm not sure, he has his uses, but he's a living model, so he'll die is he's in the lich's control area once you pop his feat. He has stealth, so any any attacks over 5" away will auto-miss. The bombs are very cool, but his range is 6"... and his RAT is bad. So if you miss with one of your bombs, Gorman is dead. because of the scatter effect, or because your opponent smacks him. He can trow a bomb, before moving but that's not always easy to set up. Then again, he can set up warjacks for the kill with rust... prevent LOS with his smoke...
Well, you can keep him, but play him carefully, if even the weakest attack against him hits, he's dead.
hope it helps
) so I have no opportunity to exchange experiences; I want to avoid buying minis useless for my battlegroup so I'll be grateful for comments and opinions about armylists here...
btw - do You have any concept of battlegroup where heavy jacks could be use effectively? 
with terminus maybe?
(the goddamn distributor failed! 
)
I won... but it was really close... 
