To solve the ghost like issues with items, especially sketchup items, make sure you go to the item attributes, textures, select the default texture and se it to none.
As for being too bright or too dark; when you are using the cycles engine you must make sure all of your walls are drawn for a room. After you have ensured that, you can place light sources around the room using the local catalog browser. To find the light sources go to ROOM_FUR>Lighting Fixtures>Light Source. After you place it, right click the light source and go to “Light Properties”. From there you can change the brightness of the light (typically between 60 and 100 Watts is desired depending on the amount of light sources) and you can change the shape of the light cone and color source of the light. You may also find it helpful when viewing a rendering to adjust the lighting properties using the hotbar at the bottom of 3D renderings. Typically turning natural lighting down, turning Artificial lighting up some, and turning user added lighting up some helps balance but each rendering is unique so I encourage you to play with the lighting settings.
If you want to use the cycles rendering engine, please make sure your computer has a powerful graphics card and that you have the check box for “hardware acceleration” turned on under Preferences>Rendering. If you do not have a powerful graphics card you should continue using EZ Render as opposed to Cycles. Cycles is much more realistic looking with lighting and reflections (especially metal and semi-transparent objects)
