Refer to your Qs:
1) Personally speaking, I think that DWE is good. The materials is designed with reference to some books talking how to teach child English, which was written long time ago or even before the publish of DWE. My daughter use it since birth. Now her English progress is satisfactory. Surelly, as a parent, you have to pay effort. Not just let the child use it by themselves. The DWE costs much but I still think it is worth because it complies different modes of teaching and learning (even I have looked at the other products). But don't expect much from their consultant who will quit very easily.
2) My daughter use it since birth but I only let her watch TV when she is eight months.
3) Yes
4) I am not sure but they may have more gifts.