Yes, you are related to every pereson who is your cousin, because "cousin" means that you have a common ancestor.
Your grandmother's third cousin is your third cousin, twice removed.
Third cousin.
Your dad's second cousin's son is your third cousin.
Your son and your third cousin are third cousins, once removed, to each other. Your son and your third cousin's son are fourth cousins to each other.
Your grandfather's first cousin's niece could be:your motheryour second cousinsomeone you are not related to (for a niece through marriage to spouse)
Your first cousin's child is your first cousin's, once removed. Your second cousin's child is your second cousin, once removed. Your third cousin's child is your third cousin, once removed.
Yes, your first cousin twice removed is still related to you.
Your third cousin may be related to your fourth cousin, but may not be. It depends on how they are related to you. Your third cousin is descended from one of your great great grandparents. Your fourth cousin is descended from one of your great great great grandparents. If the particular great great great grandparent who connects you and your fourth cousin was a parent or uncle/aunt of the great great grandparent who connects you and your third cousin, then the two cousins are related to each other. If not, the two cousins are probably not related to each other.
no
The grandson of your first cousin and your grandson are third cousins to eachother.
Your great-grandmother's first cousin's grandson is your third cousin once removed.
Your father's first cousin, once removed, is your 2nd cousin. Your father's second cousin, once removed, is your third cousin.