Tellurion

Hi! I have a couple of questions before I start my attempt at Level 3: 1. An earlier question clarified that we can bring more than 5 Kerbals along with us, such as scientists or engineers. Does everyone have to come back, or can the extras stay behind while the 5 mission pilots return? 2. After each pilot visits their assigned moon, can they regroup with other Kerbals on the surface of another moon, before returning home, or are they only allowed to set foot on "their" moon?