A - As far as grounding of RF protection goes, it helps to reduce the static charge and ELF electric fields from the protection surface.
In cases that the RF radiation is strong, the grounding might also improve the ability of the protection used to block the RF radiation.
In some cases it would be impossible to us grounding, especially in curtains, canopies.
In most cases RF protection will help also without grounding.
The proper grounding will be to the real earth outside, after you test there are no ground micro currents and after making sure that the grounding is good.
I don't recommend using the house electric ground, since most of the time it is not a "clean" ground.
My best advice on this issue is to call a professional EMF grounding expert.
Please also see "Ground loops and Ground micro currents"