Dear Khalsa Ji,
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/sikh-sikhi-sikhism/1241-respect-guru-ji-guru-granth-sahib.html

The real respect to Sri Guru Granth Sahib is when we incorporate its teachings in our life. That is why Guru Sahibs gave it to us.

The way we keep it in Gurdwaras is for its proper up keep. I explain it why I say so.

Traditionally, Sri Guru Granth Sahib was and even now being read sitting on flat surface e.g. floor. It is ease if this heavy Granth is at an elevated postion so that the reader can read it effectively, that is why Manji is needed.

We keep pillow like item on either side, below the open Sri Guru Granth Sahib. This primarily reduces the stress on its binding thus prolongs its life. In fact I even do the same even when reading secular literature if the size of the book is large e.g. big dictionary or Atlas. That is why the pillows like things are needed.

We cover Sri Guru Granth Sahib with rumalas. This is to provide some sort of protection from fine mud that is often there in the air even during wind of moderate intensity. Incidently these rumalas act as paper weights also. They protect the pages from being torn by the flowing wind. That is why rumalas are needed.

This way we see that these features are have utility.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=1241

Chandani and Chour, in my opinion are frils. They are not necessary. They make Sri Guru Granth Sahib resemble like a deity. There is no need of these unless the individual wants to its reverence to the Akaar of the Granth. I revere more the Nirakaar part of of Sri Guru Granth Sahib, which is Sikhi (teachings) that is enshirined in it.

With love and respect for all.

Amarpal Singh