Could you please show us the results of your OSM importer for FSX on a few screenshots? I am really curious about that.
Manila bay, RPLL and Makati district (notice I place "concrete" to show building footprints)
Same area from different angle, showing also the dock area
Looking north of Manila, coastline/rivers.
Not done much work on the OSM importer for months... seems to me there's quite a few ways to improve the generated scenery by considering things such as road density and applying urban landclass in areas with high density, maybe also consider elevation data to ensure mountain sides are covered in forest and not cropland as FSX tends to do by default.
Many ideas, so little time.