I used one of the early Castrol Magnetec oils in a Porsche 944 turbo about 20 years ago and it had no problems with it, checking now recommendations are to use a 10-40 grade in that model. I'm looking at changing my oil to a 5W-40 Mobil which is said to be more tolerant of the temperatures seen in the turbo bearings than their competitors products, I have used a Mobil1 0-40 in other Porsches since the turbo and it's always performed well, so I expect the Mobil Super 5-40 or 10-40 should stand up well in the small turbo engines of the RCZ.
One the subject of timing chains, while there may be some wear in the link pins on the timing chains there is also a possibility of stretching of the links which increases the wear rate of the sprocket teeth but that which could lead to links failing is less likely in my view than the probability of the plastic chain guides breaking off at the ends and so causing the chain to go slack very suddenly and hence an unexpected failure, I have seen photos on the internet of such failures which often restrict the oil pick up in the sump. Not that the oil pick up is a problem at that point as the engine is already done for. Otherwise, the chain tensioner only has a limited range so if a chain begins to sound noisy, I would get it changed and a new tensioner fitted. Very few cars are sold with a good history saying when or if a chain has been replaced.