In the side bar under 'scripts' or 'character scripts' (can't remember name), click the ... among the pop up menu scripts there should be something called ghost, or ryker's something - anything with that kind of name causes the ghost effect and the npc to only be view-able through the spirit vision skill. So you could remove that, but it might also remove the ghost fx.
Not sure about the icon thing, been getting same error myself. You could create a custom sprite and import it instead? Should be a tutorial somewhere on the editor guide wiki.
