BMW 320D - General update and review

Over the past months and years I've posted quite frequently on my 150000-ish mileage 2005 BMW 320D Touring. Some of the faults I've fixed and some are still waiting attention so I thought a quick summary report would be useful.

• First of all it's a great car, the family workhorse and feels fit for another 150000 miles.
• A couple of years ago it suffered from a strange intermittent, hesitation/running problem that was eventually identified as the swirl flaps not operating properly.
• The problem was the electrical operated vacuum actuator valve for the swirl flaps was failing. Disconnecting/blocking the vacuum pipe to the valve in order to disable the swirl flaps solved the problem! (It's still disconnected because replacing the valve requires the intake manifold to be removed. ).
• The exhaust does smoke at times under hard acceleration but nothing to cause concern.
• The disconnected swirl vanes default to the open position and so will, I anticipate, affect the fuel/air mixture and probably result in smoke creation.
• Kits are available to remove the swirl vanes as these sometimes fall into the engine causing destruction! I think these block the swirl vane intake path but the car performs perfectly well in the open position.
• The turbo developed a whine at low speed some time ago. It hasn't got worse and performance seems unaffected after well over a year. I've no idea why this should be.
• In winter it was noticed that the engine was not warming/achieving normal running temperature very quickly. The radiator air flow flaps were found not to be working.
• The radiator air flow flaps are actuated in the same way as the swirl vanes and it is strongly suspected that the failure is for the same reason. i.e. the electrical actuator valve. Again this valve is under the intake manifold and difficult/impossible to replace without removing the intake manifold. 
• The crankcase oil breather was changed after reading that, if blocked, this was potentially harmful to the turbo oil seals and could cause smoking (and in the worst case engine destruction if the seals failed!!).
• The air bag warning light started to light intermittently. The warning light was being caused by the passenger seat occupancy sensor.
• A work around of a resistor and zener diode was used as a solution for the MOT!!
• The occupancy sensor has now been replaced.