Yes.
Yes, traveling from the US to Puerto Rico is considered a domestic flight because Puerto Rico is a US territory.
No, Puerto Rico is a US territory. Its people elect their local government, a legislature and their Governor, but the Commonwealth has no vote on the floor of the US Congress. The people are US citizens and able to travel with US passports.
Puerto Rico is an US territory. Puerto Rico use the US dollar($). All citizens born in Puerto Rico are US citizens.
If you were asking "Are Puerto Ricans illegal aliens?" that would be a yes AND no answer. Puerto Ricans are considered immigrants because Puerto Rico is not part of the United States (its not one of our 50 states), but it is US territory (we protect them and stuff). :) hope this helped you :)
No, it's a non-incorporated US territory (or colony, if you wish).
Puerto Rico.
Puerto Rico is a US Territory and its inhabitants are US Citizens! So, if they are US Citizens, any US citizen can live in Puerto Rico.
Puerto Rico
For the same reason that some one from New York who moves to California is not Considered an immigrant. Puerto Rico is part of the United States. Puerto Ricans are US citizens by birth since 1917.
There is no President of Puerto Rico. Puerto Rico is part of the US, so the President of the United States is the head of state for Puerto Rico, as for the rest of the US.
Puerto Rico
Puerto Rico uses the US Dollar.US dollar($)