During the event, can we take turns running up to the controls?

No. For safety and competitive reasons both team members must stay in contact throughout the event. In practice this means you cannot have one team member take a short cut whilst the other climbs up to a control. Some controls will be marshalled and marked as such on the control description sheets, but there will also be secret marshals at some controls. Any team failing to visit a control together may be disqualified forthwith.