His first hand is pretty much a bluff, his bet shouldnt be for value and he will want to take advantage of picking up the pot on a scare card. He is playing the board there and not his cards. In that hand [other than folding preflop] I would bet that turn harder, your bet is very weak and you dont want a call.

I never really show my bluffs, they do give you more action, but you dont always want that action. If I knew I was getting KK in a few hands then sure, Id bluff and show it, but what if in the next few hands am card dead and just want to pick up a few small pots? Whatever floats your boat really, I dont think its horrible, I just dont personally see much of an advantage from it with my game.