secondary badge is used by pressing right on the DPAD.
The symbols i believe are assists, kills, teamkills (negative xp) and overall points.
Also you cna only have a set number of sentry bots per map, some maps (very big) have up to 4, medium have up to 3 and small usually 1-2. THE BOTS DONT FLY AROUND THE ENTIRE MAP, THEY STAY ON THE IMMEDIATE AREA WHERE YOU DEPLOY THEM.
Cool. Also do you have any idea how you mix and match the abilities? I know you can mix and match and create a hybrid class, it mentions it in the manual but doesn't tell you how to do it.
you have to get all the badges/ribbons for the class and then you can mix and match it eith other classes