Was the Declaration of Independence legally binding?

Answer 1

In the sense that it declared independence via a possibly-legitimate governmental body (the Continental Congress), yes.

In the sense that it set any legal precedent or law for the new nation to follow, no.

Answer 2

It was essentially a death sentence for those that signed it! beyond legally binding, it was treason at it's most extreme and obvious. Had the United States not won the Revolutionary War, it is very likely these individuals would have been tried and executed for treason.

The Declaration of Independence was a statement of contempt for the way that the United States citizenry were being treated and a statement that we would no longer except the law that we were currently being subjected to.

It was very much a binding statement in which anyone signing could not go back to the way it was before the signature. It was, as one writer stated an issue of "Liberty or Death".