@ OPB to change either my pull down menu background or rosie app drawer background (after flashing mod already) - can I simply change the corresponding files with new ones without reflashing the mod? Or do I have to change the files using my PC, transfer to phone and flash in recovery?
yes, basically you have to get what you like the image ..and replace the files put in both rosie and systemui drawable Xhdpi folder
and reflash under recovery