So thoughts on this:

Vader, SA 46
2xBBSV 40
Thrawn 32
Xizor 30
Tarkin 22
Mas 8
R7 Astro 8
2xGran 8
2xUgos 6

Map is ravaged base or throne room.

I could dump tarkin for Ozzel/Lobot, but I like quading BBSVs for 120 regardless of whether an enemy is activated or not.

NO

I guess it can work but the Bith are still only a 10 attack unless they are within 6.I guess they are a 14 with opp or 18 within 6. And I dont get the point of even asking if you should add ozzel. I think your trying to do too many thinks at once. I think the Vader,Rex,Commanders just works better.

Keep Tarkin. I dont think Ozzel/ Lobot are worth the swap out for the damage output you gain by having him in there.

Other than that, my only suggestions would seriously alter the squad.

My son and I played a fun game with Xizor last night - I fielded an Aqualish Assassin swarm squad, but with Xizor in place of the typical Ithorian Commander (the bonus is the same) and I further pumped them up with General Whorm Loathsom so it was actually a Sep squad, with Whorm the only Separatist. Twin attacking AA's are nasty when they hit at +15 for 30, and I had eight of them. I didn't optimize the squad by any means, but I think there's some potential with Xizor if you can stack his offensive boost with another faction's bonuses.

Yeah I love Xizor. I just wish he had 20 damage.