When you take the intake off make sure to cover the intake tracks so nothing falls in there. That would be a bad day.

Also use a torque wrench for everything. If replacing vacuum lines be careful with the connections as they will be brittle, especially the EGR actuators. I’d probably just keep the original section attached to those and use a coupler.

Also, there is a specific tightening sequence for the HP EGR cooler rear the radiator. Follow that or it cracks eventually. If you will keep the car for a while you should really get ISTA+ off eBay if you don’t already. Also the Bimmergeeks is a reliable OBD to USB interface. It’s pretty much required and is very helpful. It has functions to test essentially all sensors and systems.