What are the advantages and disadvantages of have the wing positioned further aft on an airplane?
The overall centre of lift must be coincident (in the horizontal plane) with the centre of gravity, otherwise the plane would tip over forward or backward.

Since most planes have a large wing that contributes most of the lift and a small horizontal stabilizer that only contributes a little bit, the main wing needs to be close to the centre of gravity. So the wing is mounted further aft if the centre of gravity is further aft.

Now the cargo will always have its centre of gravity near the centre of the fuselage. So if the empty aircraft has aft centre of gravity, loading it will cause larger change of the CG position and for this it needs larger horizontal stabilizer so it can provide enough balancing force.