The cam sensor is G40 iirc. N205 is the VVT adjuster solenoid. The fault codes you'd get for a broken cam sensor are usually "implausible signal", "Short to ground/B+" or "No signal". The ECU is good at seamlessly adapting around problems, hence why it might feel normal.
The only issue I've seen with the cam sensor is it getting covered in swarf, which I think is the metallic dust from worn down HPFP cam followers. When it gets caked in enough swarf, the ECU can lose the signal and the engine feels a bit flat, but doesn't throw a code. As you have a code in the ECU, it's likely not that particular issue, but worth a check.
The P0016 error is more specific to the crank to cam alignment being out of sync, which is usually due to timing drift from a worn chain/tensioner.......or a cam belt change a tooth off......or a VVT adjuster that's malfunctioning.
Special tools for the chain replacement are the cam locking tool and the posi-drive socket for the VVT housing bolt. I got both of those from VW as I don't trust flimsy pattern tools. There is a full write up for the chain replacement in this forum, but one bit of advice I can offer is get an assistant to press hard on the breaker bar whilst you undo the VVT adjuster bolt. It's a very shallow headed bolt that strips out mega easily if pressure isn't applied to it whilst undoing.