"The discovery of hundreds of exoplanets in the last decades have revolutionized the field of planetary astrophysics. The properties of many of these systems turned out to be quite peculiar and very different from our own Solar system; they gave rise to outstanding puzzles and opened new avenues for processes involved in planet formation and evolution. In our own Solar systems the last decades have brought the discovery of binary planetesimals, new minor planets in the trans-Neptunian regime and many new planetary satellites. Taken together, these new horizons open the path for major breakthroughs in our exploration of planet formation, dynamics and evolution. I propose to study multiple systems in the planetary regime, where dynamical processes can play an important role, both through strong scatterings and collisions as well as through secular processes, and strong interactions with the environment. At the small scales I will explore the role of binary planetesimals in planet formation and their evolution; these are important both for the early stages of planet formation in general, as well as for the long term evolution of planetesimals in our own Solar system and their observed properties. At a larger scale, I would explore planetary satellites, suggesting that dynamical scattering processes studied in the context of multiple exo-planet systems could play a similar role in the structuring of satellites systems and the origin of irregular satellites, and potentially exo-moons. Finally, I propose an extended research program about multiple exo-planet systems, focusing on their size/mass ordering characteristics, and making use of these yest unexplored properties to learn about the underlying physical processes involved in their assemblage. The study of these various topics can make use of similar tools, and together shed new light on major aspects of the evolution of planetary systems, their origin and their overall characteristics."