Question

Where did most of the interplanetary fragments in the outer solar system get flung to by the larger gas planets?

Answer 1

According to the condensation theory:

Over a period of hundreds of millions of years, many interplanetary fragments in the outer Solar System were thrown out by the jovian planets to the edge of the Solar System. These interplanetary fragments form a theoretical cloud of predominantly icy planetesimals known as Oort cloud.

The Oort cloud is proposed to surround the Sun at distances ranging from 2,000 to 200,000 AU (0.0 to 3.2 ly). It is divided into two regions: a disc-shaped inner Oort cloud (or Hills cloud) and a spherical outer Oort cloud. Both regions lie beyond the heliosphere and in Interstellar space.

The outer limit of the Oort cloud defines the cosmographical boundary of the Solar System and the extent of the Sun's Hill sphere. The outer Oort cloud is only loosely bound to the Solar System, and thus is easily affected by the gravitational pull both of passing stars and of the Milky Way itself.