Regards to the splitting/assymetry issue with Roxie, V4 and other figures: Are you using the dev rig with the morph brush symmetry or the production rig? Roxie's production rig/mesh seems to be assymetrical when exported to zbrush, but the dev mesh is symmetrical. I can mirror a morph in zbrush across the dev mesh. I can't mirror a morph in zbrush across the production mesh. 

V4 doesn't split in zbrush when using GoZ or when importing directly from the geometries folder. At least I've never seen it happen. I did a tutorial a while back on how to use GoZ to create morphs in PP2012:

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3975663

Never have had to delete any verts on her. If you're exporting from inside Poser manually then the export settings can get confused and sometimes it just doesn't work correctly even with the right settings.

 

~Shane