Hi Fabien,
Thank you for your Interest in Syncfusion products.
1) You can bind the collection in the GDBG. The following code explains the same.
ArrayList array = new ArrayList();
array.Add(new MyClass(001, "John David"));
array.Add(new MyClass(002, "Tom"));
array.Add(new MyClass(003, "Bretney"));
array.Add(new MyClass(004, "Jessy"));
array.Add(new MyClass(005, "Bruch"));
array.Add(new MyClass(006, "Johny"));
2 & 3 Hope this is helpful for your reference, Please refer to the following UG link
http://help.syncfusion.com/ug_94/User%20Interface/Windows%20Forms/Grid/Documents/522howtochangethebackcolorofacolumn.htmPlease refer to the sample link which is illustrates the same.
http://www.syncfusion.com/downloads/Support/DirectTrac/87069/GDBGSample-2118917405.zip Please let me know If you have any further concerns.
Regards,
Ragamathullah B.