I didn't really look over the list in great detail tbh. I wasn't planning on going into lots of detail, I just wanted to correct some of the advice you'd been given but, hey, here we are. I love discussing Necromunda dirty tricks and Goliaths and Delaque in particular.
I like Forge born over bullys. For 5 creds more than a Bully (With the vat born upgrade that makes them S4 *Edit - overdeveloped musculature*) you get bully stats at M5 who can take weapons from the trading post later in the campaign. You'll get plenty of free bullys anyway if you're playing a Dominion Campaign, from your settlement.
I'd start your bullys/forgeborn out with two Stubguns and then build up to an axe. Twin stub guns give you 2x shots that hit on a 4+ if you're within 6", due to short range modifiers, which makes them quite dangerous. A Forge Born with S4, 2 x stub guns and furnace Plates is 55 creds. Bargain! If creds are tight to start with just give them a single stub gun for 1x 3+ shot at 6" and no plates for 45 each and level then up as you go. Unarmed S4 is still really dangerous against most standard fighters.
My favourite Stimmer build to date is unborn with infiltrate, docs experiment - 1s, +1W, scar tissue, paired spud jackers and a stimm slug stash. If you take a chem dealer hanger-on after game 1 you can get him a Frenzon Collar on credit and thank me later.
If there's creds available, incendiary grenades are quite tasty too.
Forge boss with grenade launcher is good, so is heavy Bolter. Depends how you want to build your gang. Heavy Bolter is expensive as hell though esp if you want a suspensor (And you really do) so might be better left till downtime recruitment. I actually went with a missile launcher, with my downtime spend, which is amazing for just 5 creds more.
In my last campaign I gene smythed my grenade launcher forge boss to have the one that lets him have group activation +1 and access to ld skills (*Alpha's Lineage) , and then gave him a further +1 to group activation with one of the LD skills (*Commanding presence) for group activation (3). I then dished out 2 frenzon Collars to Forge born and gave the activation button to said forge boss so he could activate both Forge Born and the Stimmer and himself in a single activation no matter where they were on the table. A veritable wall of muscle! It was quite effective.
You can't do it from the start but if you pick the right gene enhancements and skills you can build up to it quite quickly. Just make sure you always have enough creds to pay the Chem Dealer if you buy on credit. The Chem Dealer has the fixer skill too and is an absolute bargain for 30 creds.
Incidentally, I won all the triumphs in that campaign against some really filthy gangs.
It was a lot of fun.