cryrid is right. Micromesh is completely polygon-dependant. What you could do is use the ZRemesher function to generate a mesh with less polygons whilst preserving the silhouette.
lots and lots of overlapping polygons from the looks of it. using the union tool might help, but i dont recommand it since it sometimes mess up the polygon flow
That's because the extrude option is set to "by polygon" and you want it to be set to "by group". Click the arrow next to the 4 squares icon under extrude polygons
Nothing really negative to say, they seem well optimised. Just remember to delete hidden polygons if you haven't already (polygons underneath the model).
Polygons are polygons; regardless of the program. ZBrush doesn't average the vertex normals, but if you import the mesh into another program there shouldn't be any visual difference.
You also might want to look at the polygon flow on the "stretching" areas - they may have longer, thinner polygons causing the noise to be longer and thinner.
nope thats max, it sorts the objects (not polygons, polygons inside an object is another thing) in order of their first creation, sounds crazy and yes it is o_O