your unwrapping looks fine enough, but you can manage to fit it all on just one uv map, just mirror the torso, hands, back of the head, and i guess those leg things, for seams, a good trick to use to cover seams up is to use a base color that blends in the surrounding area (like a skin color, if your covering up skin seams), and paint across the edges of the unwrapped areas with that color at full opacity, this will make sure the seam edges are the same color value thus blending them when looking at your model