First of all, clear the faults and then check again after a few engine cycles. If the faults reappear then the are definite faults.
The engine mount is electro-hydraulic which means an electrical signal is applied to the mount to alter the hydraulic "firmness". It means that engine vibration is better damped throughout the rev range. Common failures on the b6 and unless your engine is noticeably rattling about, don't worry about it. It's the passenger side mount that has the electrical connection. OE mounts are about £100.
The G65, as said above, is for the air con. The sensor is located on the air con condenser, the smaller forward radiator on the front of the car, passenger side. If the wiring checks out then a new sensor will cost you about £30-£40. If you press the ECON button on your A/C control and the red light fails to go out then this is a definite hard fault. It could also mean that the air con system needs regassing, hence no pressure in the system. This can be checked in VCDS in HVAC measuring blocks.
Positive charge pressure is an overboost from the turbo. The VNT vanes within the turbo have failed to open when required boost has been reached. This will likely cause the engine to go into Limp Mode which should clear with an ignition cycle. The possible causes have been listed above. Personally, I would try the
Mr Muscle trick and check the integrity of the vacuum hoses. Then consider a replacement N75 valve (controls the turbo actuator arm that opens/closes the turbo vanes) approx £40. If you have a registered version of VCDS, you can perform Engine Output Tests, one of which is the N75 and the actuator arm can be observed for free and smooth movement if you stick your head under the bonnet.