How to set multiple margins in the property panel?

1. I need to set both bottom-margins and horizontal-margins for different sizes.
   It seems that this is not possible in the property panel as just 1 margin is presented.

For setting multiple margins I have to enter them in the Code-view.
Why not using the DW-way by using the 4 margins?

2. Why the margin-settings are restricted to 5 ?