Article IV, Section 1 "Full faith and credit" applies only to the fundamental rights enjoyed by US citizens. I think it was written mostly or the benefit of legal judgements. For instance, your marriage is valid in every state no matter where you get married. However, the fact polygamy is legal in state X does not confer that right automatically to residents of state Y simply by virtue of it being a right in state X. The states have the right to set overruling local policy.
Regarding Article IV, Section 2, In Corfield v. Coryell (1823) Justice Washington wrote, "[W]e cannot accede'' the opinion proceeds, ''to the proposition . . . that, under this provision of the Constitution, the citizens of the several States are permitted to participate in all the rights which belong exclusively to the citizens of any particular State, merely upon the ground that they are enjoyed by those citizens;..."
That about says it all.