My group is unsure if we have been doing this right. Minion damage is it one weapon applied for example 7 on a group of 4 minions with blaster rifles or is it 28 on a roll for 4 minions?

Sorry for the poor wording

Just the one weapon [1W] damage, plus successes. If you are rolling for four minions, upgrade the check three times. So the minion has GGY for shooting… the next two minions make it YYY, then you add an extra G, for a total of GYYY.

The only thing I don't like about this is you can really nail one character at a time. This might make sense for coordinated troops like stormtroopers, but doesn't really make sense for a band of thugs.

Well, in that case wouldn't you simply make multiple groups of minions? Or give them an autofire weapon?

Yea. Instead of having one group of six minions, use two groups of three. It makes their attacks and HP way less, and it takes a lot of the heat off of the players early. For major challenges, make a stormtrooper squad of five led by a sargent. **** could get real pretty fast that way.