Any collimated (or nearly collimated) laser beam or white light source larger then 100µm and smaller than diffractive element aperture.

The angle between points can be altered using simple lenses, but individual beamlets will also be affected independently of the pattern (e.g. collimating diverging pattern will also make individual beams to converge and then diverge after passing through the focus point).

Varies, typically 5%-25%, depending on the pattern. Large patterns will have lower uniformity due to a drop-off in intensity in the outer points.

Approximately 60%-80% @ 633 nm