The shafts that walked out can cause oil leaks. Set the cylinder to TDC to take the pressure off the rocker (make sure you're on TDC not over lap) Loosen the shaft (you may have to make a special tool by grinding off a allen wrench) Set the shaft in correct position then tighten. Your only problem is you wont be able to use a torque wrench on them. Tighten them as tight as you can get them (should be 21 foot pounds). That part you have circled is a valve to allow warm air in the intake on cold startup to prevent icing in the throttle body.