'Empty hand' doesn't always mean literally empty - it is supposed to signify the clearing of the mind and body in preperation for training. It also signifies 'empty of any evil intent'. There are many karate clubs that incorporate weapons training, especially traditional Okinawan style clubs. However, a lot of clubs do borrow weapons and aspects from other styles too. For example, there are Shotokan clubs that train with kobudo weaponary, even though Shotokan is not a traditional weapons-based system. As for the grapplig, there is a lot of that in karate. It just depends on your instructor as to how much you do. Karate isn't just about kicking and punching, but sometimes the other aspects of it have to be 'looked for'. Your right every art is not complete.