Answer:
1. Freedom
2. Because the will have their own rights, because Americas a free country
3. They might feel bad, leaving everything they knew, but some might say its okay, because they just want to be free.
A non-restrictive modifier add information that does not restrict who the subject can refer to (compare to "The one Marlena that enjoys many subjects" -this one restricts the subject to a specific Marlena). Here it's "who enjoys many different subjects" - it adds additional information about her, but doesn't change the referent.
