The declaration was a laundry list of affronts to the colonies by King George III, wherein Jefferson et.al. argued that since the monarchy did not treat the colonists like other Britons, the colonists had the right to form their own sovereign nation. It was also intended to justify this action to other monarchies to prevent them from helping Britain retain the colonies under the doctrine of Intervention. So it helped to justify the war domestically and internationally.
To rejoin the union hopes this help
A i think the others dont seem related to the holocaust
The government did a recall on him
No because the war started a year before the declaration of independence was written.