When making a preset it is always best to save it as a .png for a better quality, also to remember to change all the .jpg's in the material file to .png's
The reason your preset is not exporting might be just the material's fault. What I suggest is getting a material file from a preset folder/material file that DOES work then change all the numbers inside it. That seems to work for me all the time. If not, you may have to switch to a different folder.
As for you not being able to see other people's preset, the white/texture-less characters you are seeing have Marking packs (custom made markings made by other people that can be found here (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&board=22.0) or here. (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&board=34.0))
If you want to see other people's preset, ask them for their .fhp file of ther preset (found in FeralHeart\\Presets). Then once you have that file, save it into YOUR FeralHeart\\Preset folder.
Hope this helps. If you have any problems or questions to ask, come back! :)