#1 Good soft light on him but watch your white balance, it's a bit blue, making him look very very pale. The background is very bright and busy... be careful with that.
#2 Interesting, kind of humorous. I don't think it works well by itself, but perhaps if it was with a series of similar images of him it would be nice. There's just not enough information here to have any idea why he's there, what he's looking at...etc.
#3 Technically it's okay for what it is. I find the harsh orange lights to be a little off-putting. Perhaps a B&W conversion would be appropriate?
#4 Exposure is spot on and you even got a little catchlight in his eyes. I like the framing and light quality for it being a quick grab-type shot. I personally don't get into seeing people's tongues though, but some might think it's cute.