I'm with ridevfr on this one, leave the bobbins alone. It doesn't matter how shit your bobbins are, they will not cause brake drag. Just because an idiot posts a video on turning your bobbins, doesn't make it true. The same for wheel centre, you have floating calipers, unless your wheel is out by a shit load, that won't be it. Make sure your caliper slide pins are clean and greased. You will be suprised at how much crud builds up behind your pistons, and at the bottom of your master cylinder. Brakes need bleeding every year, and a major clean every 4 or so years. It doesn't matter how many miles you do, or the type of bike.