That's definitely a rather low density. Maximising UV area utilisation does not automatically mean texel density will be sufficient, it depends on a triangle of factors: Efficient Unwraps (including how much surface area there is to unwrap within a textureset), target texture resolution, and physical size of the geometry.…
The bake rays are intersecting with neighbouring geometry, particularly as these appear to be non-contiguous pieces. It also looks as though the resolution/texel density is quite low. The best solution would be to use Bake Groups, followed by exploding the model, followed by fiddling with the ray distances until you get…