Hi Mate, list looks good however for me you have way overspent on Core, ideally you want to be aiming for as close to minimum as possible (375 points) and use the rest of your points in Special or Rare.
Here is what I would play with at 1500 using the Core of your List with some explanations underneath.
SO Level 4 - 305 pts
Fencers Blades, Shrunken Head, Obsidian Trinket
BO Big Boss - 165 pts
BSB, Armour of Fortune, Sword of Striking
Goblin Big Boss - 66 pts
LA, SH, Wolf, Draonhelm, Tormentor Sword
Goblin Big Boss - 64 pts
LA, Wolf, Enchanted Shield, Dragonbane Gem, Warrior Bane
28 SOBU - 343 pts
Add Hand Weapons, Full Command
5 Wolf Riders - 55 pts
6 Trolls - 210 pts
Doom Diver x2 - 160 pts
Mangler x2 - 130 pts
Ok so I don't think that you'd need the Goblin Shaman with Dispel Scroll, I usually play without a Scroll and don't find it really hurts me that much (usually the Dreaded 13th Hurts the most)
Your Level 4 now have Magic Resistance which goes onto the unit upping the Ward Saves versus a lot of direct damage magic, the BSB has a magic weapon as well as the level 4 incase you face ethereal units/characters that you do not want your Level 4 to face.
I feel that you need more re directors hence the two Gobbo Bosses on wolves, these have 2++ versus fire so you can hold up flaming units/characters (A gobbo facing down a Bloodthirster/K'daii Destroyer is hilarious) I have replaced the Goblin Bus with Trolls as they act in much the same way (tarpit) but can put out a decent amount of damage
Hope that helps