If you love that wallpaper, use it in bathroom. Not really right for behind bed. I would go a drum style chandelier. In a silk pale gold. Your bed looks zen or Asian to me. I love it. But, you don't. Need to much with it. Keep it simple a more formal drape on windows, color would depend on wall color and bedding. I'm thinking a dramatic peacock satin. Use a lighter same tone on walls a rich teal. Ceiling can be gold leaf. With alight that cast shadows on ceiling at night. Then your wall paper will tie in. Furn should be mirrored.

It depends on the style of your furniture and home ,if you can , please post a picture of the room ,stair case in question this would help .

Rules can be tricky, because it really depends on the chandelier, for example, does it have a small metal part in the middle or any crystal pieces which hang lower than the majority of the chandelier? We like to be able to see underneath the main part of the light fixture, when standing beside the table - if for example you were using the dining table to serve buffet style... or for a wine tasting. It's best not to cut too much of the electric wire or chain until you're sure you like the length. I hope that helps?

Arun, it depends on the chandelier brackets. suggest you to check with vendor.