Seriously. I understand why people are getting confused by this, but people need to PAY ATTENTION a bit more i think. I have not seen anything on youtube about this game that states this fact, and i really believe that people are being misled by their experiences in other video games on character creation.
YOUR SPECIALIZATION ON CHARACTER CREATION ONLY DICTATES YOUR STARTING GEAR. THAT IS ALL. THERE ARE CURRENTLY NO RESTRICTIONS ON ITEM USAGE.
Some of my favorite combinations that prove this:
Plasma cannon (or any heavy weapon) with jump pack armor. (this probably SHOULD be restricted)
melee weapon + pistol and missile launcher armor. (great at clearing ranged trash while i beat a dreadnought to death)