Ive played this game for a while and ive noticed that some of the combo mods dont always have that insignia next to them. Ive seen this on the other javlins and its just as much of a let down that not all can be used in combos, especially the ones for storm.....the javlin that excels in combo set ups. I hope i discover more combo mods to prove me wrong but again....this issue of some combo nots not being able to combo is a bit of a damper.
I'm not sure what you're saying here. If it has the bullseye, it's a primer (sets the combo up). If it's the star, it is a detonator and that grants a combo. Not all gear is a primer or detonator, but consider the synergy of a 4 person squad; Storms kick * at setting up combos from a distance for the Interceptors and Colossus to detonate. Maybe you run with another storm so he has primers and you have detonators. The non combo related items look to me like they make up for not being part of a combo by the amount of damage they do, or the range on the ability- stuff like that.
But no, not all gear is going to be combo-oriented.