First post. To increase finger speed? Put your hands in playing position wit your finger tips touching a flat surface. Leave your fingers tips in place, but press your palms into the table so your fingers have a drastic claw type curl, then press each finger individually into the flat surface. It's an isometric contraction. Your fingers and hands wont move, but the muscle will flex. Push as firm as you can for quick bouts. I just tried it by rolling my fingers thumb to pinky and back.
That might help. Try it out. What could it hurt?
I play piano myself. Maybe ill give it a go.