Wray; To correctly answer your very specific question - the answer is TWO INSIGNIA. (See 3.E.1)
Past that, you may also wear up to TWO DEVICES. (AKA Command Pins) (See 3.E.2)
..and finally, you may wear up to TWO badges. (3.E.3) (Only certain badges may be worn together and only some are authorized post-icumbency)
This applies ONLY to dress uniforms. The ODU allows only incumbents to wear only SOME Badges and only incumbents to wear their DEVICES.
Knowing you - I would say the answer you were looking for is actually the first one - two qual insignia. You may see some folks with UP TO 6 'pins,' but that is usually limited to senior BMs.
The only possible way I could read Seven as being right would be if someone was at a joint command or a cabinet level office which has it's own "ID Badge" pin like say DHS, had been command afloat and ahore, has two different permenent qual insignia and has been a Full time Gold/Silver Badge CMC and an RFMC.
