RE: BRUSHED MOTORS
In a word, yes. You can use more or less turns of heavier or thinner wire to change the characteristics of the motor. Fewer turns of wire makes the motor spin faster for a given voltage. More turns makes it spin slower. Thicker wire allows the motor to handle more Amps, but extra space it takes up might limit how many turns of wire you can physically fit on the armature. Thinner wire will allow you to put more turns on the armature, but will limit you to how many Amps you can put through the motor without burning the wire out.