Here's an interesting thing on the techs Scott.
Watch the scenes at the Command Center closely, and the dude with the headset communicating with the pilots directly. He's actually wearing a completely different uniform. Instead of a jumpsuit, he has a shirt that's cut exactly like the Fleet Trooper's (or han's at the ceremony), and pants that I'm not sure you can see.
I've always considered him a "Technician Commander". He's one of the only guys in this uniform you ever see.
Techs are everywhere though, for sure.
As for the hat, I am not so sure it's in the movie at all. In the Expanded Universe, either Rebellion or Empire comic series, there's a story that involves Leia's ship and the troopers are wearing grey caps when they're not in a combat situation... Kind of like our own military. I love that detail though as it makes sense they'd have a cover for their downtime.
I've scanned the ceremony sequence for a while now and never noticed grey caps on any Fleet Troopers. There are TWO distinct types of "Officer" uniforms who are wearing caps though, and they have a red/yellow/black design on the caps in some cases (with a shorter brim). These guys are in a more relaxed style of uniform.
Then there are other officers with a longer-brimmed hat in a more fitted uniform, and ascots. The best shot of one of these guys can be seen behind Leia for sure.
The only place I've seen the trooper with the "Flare" band on his leg is standing in the front row at the medal ceremony which is kind of odd.
Those things on the leg were on pilots legs in WW2 and had flare cartridges in them. If I can find a pic of a 1:18 pilot with them I'll post it. There are some German figures with them I know. I like the extra gear... The pike would've been nice too but like I said, I'll live without that if it's nixed. The extra bits like the scanner gun, leg flares, and cap are really nice though. I just wish he had a friggin' holster, haha.