Unresponsive: YOu can clean your bearing, which takes all that junk out of it, making it spin better The link for the tut is : http://yoyoexpert.com/forums/index.php/topic,871.0.html . You can also silicone your yoyo. YOu will find many good tuts for this on youtube; just search “How to silicone a yoyo”. A great tut for siliconing a yoyo is on highspeedyoyo.com. The link for that tut is http://www.highspeedyoyo.com/modding/installing-red-rtv-in-a-yo-yo . Also, you can screw around a bit with the adujustable gap. it will make the gap larger/smaller and help the unreponsive/responsive factor!
Responsive: Buy some thick lube from YYE. The link is : http://shop.yoyoexpert.com/product/58/YYJ-Lube . Just put some on the sheild of your bearing and play it a bit. Also, you could just tighten the gap.
You can silicone recess, satin, schmoove, etc. a kickside. I would personally leave it as is. Why would you ruin a perfect plastic?
Advanced tricks can be done on a kickside. I can easily complete eli hops, yuuki slack, and more on my kickside. its a great yoyo
4.Again, clean the bearing. It will take all of that crap out of yourbearing and dissolve it. (hair, lube, etc.) Again, The link is : http://yoyoexpert.com/forums/index.php/topic,871.0.html .
Hope this helped!