So many lens, so little time!!!

What exactly makes a macro lens "macro". I bought a 50mm 2.5 about a year ago mainly because I needed detailed shots of some of the products I was shooting. It takes incredible photos. I've been using it to shoot some of my kid shots in my studio as well - the clarity is fantastic except that I find I'm getting lots of blurry photos in the bunch. Could that be something associated with the macro lens or is it more likely an f-stop issue?

Second question - my first lens was a EF-S 17-85mm 4-5.6. I absolutely love the focal lengths it gives me but the clarity is just not there. Is that because it's an EF-S lens and not an EF lens?

Third (and last) question - I've been shooting some taekwondo testings and I can't seem to find the perfect fit between environment and lens. This last weekend, I tried again with an 85mm 1.8 but I couldn't get close enough to make it work. Ended up using my Tamron 75-300mm 4-5.6 which seemed to get close enough but wasn't fast enough to accommodate for the terrible gym lighting and the fast action. PLUS, I wasn't able to really blur the background and focus in on the action. Any suggestions?

I know - lots of questions - I'm a beginner and need a little nudging in the right direction. Thanks!!