Thanks! I tried stars.svgz again.
1. You seem to disregard the item's transform when exporting it. This only works for paths with "optimize transforms" mode. You need to multiply each point of the path by sp_item_i2d_affine(item) so that it works for shapes with transform=.
2. After I worked around 1. by converting all stars to paths and moving them a bit so as to optimize their transforms, I got something which at least looks like the original in terms of the shapes and their relative positions. The good news is that povray does not crash on it, at first. It still crashes nearer the end of the render with:
Possible Rendering Error: Maximum trace level reached! If your scene contains black spots read more about the max_trace_level setting in the documentation!
line 2: 8174 Segmentation fault pv istest.pov
3. It may be due to lighting, but most of the stars are pure white, some are yellow and some are black. This does not look like the original colors. At least part of the reason is that you disregard the transparency of the shapes, but there are red and green stars there which I don't see in the pov render.