I will have to agree with you... there has go to be a trick to it... people use inkscape all the time and create some great parts. I really don't think the pixel thing was a problem, there may be something else, just don't know what it is. inkscape seams to be pretty limited on .svg export options. If you are creating a part wit the FZ Parts Editor, when you load the .svg into the selected view and save the part, FZ error checks and rewrites the .svg then saves it into the specified folder. That is the way you are supposed to to create a new part. I create new parts and edit old parts a number of different ways... but I am not using inkscape.
Most of the original core parts were written using Adobe Illustrator, back in the days when when you did not have to pay monthly fees. Some of the Illustrator users moved to CorelDraw because they did not want to pay those monthly fees.
A problem I sometimes have with importing .svg files from Ink or Ai, they all have a little different format and some times they do weird thing, the image will disintegrate or crash the program. Sometimes I find it easier to make a part from scratch then to clean up a converted file. .svg files have a whole bunch of rules and different formats, FZ does a really good job of converting them... The Parts Editor seams to be able to convert all three most of the time. even in the FZ .svg file, the text is not sized in points, it is a number that I can't figure out what it means.