2) Vacuum valves behind vents bad or leaking; dash has to come out to replace them; vacuum valves are cheap.
3) Need to replace a small plastic clip (cheap) that usually brakes off; easy fix is to drill old one out and bolt new one in.
4) Reconnect linkage as it was before; dangerous condition that can lead to throttle stuck open and if driving you may have a slingshot Mercedes accelerating without control.
Karl