KEEP the products in big boxes so they don't get damaged! They are delicate instruments! Especially violins!!
bowl or container-but also (rarely) capability (like, KRS ONE has more rappin' capability than Pharrel)
arms: unlike the related term 武器(ぶき）, 兵器 generally means things that are very modern and big: bazookas, missiles, rocket launchers, howitzers.
skillful, dexterous. Like a kung-fu fighter that can jump around and not get kicked, or a pianist who plays hella difficult pieces without any fucked notes. There is also an implication that the person can improvise!
A tuba is a BIG instrument.