Question

I have two questions:

The first being why exactly my Box2D Body is twice the size of my GameObjects size? I am probably doing something wrong, but it seems odd that the two are aligned perfectly, so the units between my model and my renderer match up.

Second question I have, is if I can somehow change the projection the SpriteBatch uses to place objects on the screen, instead of moving my camera?

The picture here explain my two problems quite well

Answer 1

1. I think you used setAsBox() method on your PolygonShape. this method only takes the half-width and half-height of the box. So if you give it the full size, it will be twice as large and twice as high.
2. spritebatch.setProjectionMatrix()