(PS5, Fluorescent Lighting) - MyStudio PS5 Portable Table Top Photo Studio Lightbox Kit with 5000K Lighting for Product Photography

Will these look good even with my iPhone?

Are you able to manipulate the structure in order to shoot objects from above? I am interested in shooting plates of food from a bird's eye view.

Is there true-black backdrop, light-absorbing material or something similar so I can create a completely black background with MyStudio?

Has anyone tried to photograph jewelry? I am thinking earrings, bracelets, necklaces, rings, nothing real big or bulky.