Export vector PDF issues

I am trying to export a scene to a pdf vector to edit in illustrator. I have some transparencies I set up the opacity to 0 so I shouldnt have problems. But still I got that 0 transparencies black. Some other colors turns itself gray and also I found if that I have in the same face a furniture from the warehouse it convert the color of the face to gray (like a chair in a slab) If I move the furniture a mm upwards then I lose their textures. A completely mess, any clues?