The "body" of the Constitution is indistinguishable from the amendments because the amendments are enacted in accordance with the body.
I disagree. The body of he Constitution establishes the processes of the government. The Amendments limit its scope and powers in certain areas, and in few cases change the process of government (Amendment XVII). The Amendments follow the body; they are numbered in order.
The Constitution had to be in force before Amendments were added. The Constitution could not be in force until it was ratified by several States. After ratification, the Bill of Rights did not come into effect until 1791.
You only explained a clarification of the Second Amendment. I'm curious as to what else you meant by saying that you could imagine a better constitution.