I have to agree with everyone else, you need more gangers. I think 3 juves is fine though. I only used a hand flamer once, it worked great, but I only ever used it once in all my games. Granted my delaques were more of a shooty gang, so I only had one small group that I used for
CC, two if I really needed them. I have built gangs with both one heavy or two. I say if you have the points go ahead and get the second, but not at the cost of losing a ganger. I would prefer having 5 starting gangers. I would also drop the frags and pick up man-stoppers for my shotgun. I also like auto pistols for my juves if I have the money.
So I would have leader, 5 gangers, 3 juves, and 1 or 2 heavies based on money. I would then divide these up into smaller groups based on weapons, skills, objectives. Chances are your heavies will be staying back and providing cover fire so a back up pistol may not do much good if the heavy weapon misfires, due to being such short range. I would think a misfire will happen more often than your heavy getting into short range or
hth. Remember my experience is more with a shooty gang that also had vents to start.
I usually threw a juve in each group to use as shields. Not very nice, but what would you expect in the underhive.
Don't get discouraged either if you lose members, you can come back. We had a guy that lost 2 leaders in the same gang, one of them in the 2nd or 3rd game. It all added to the story as one of his juves ended up as his leader. That is how he lost his 3rd leader, through a challenge. Anyway Necromunda is an awesome game, enjoy it.