I can confidently say that this rumour mill would be better-suited to the "salt truck" guise.
the 2.0L engine producing approximately 320 hp
Just like the JDM Legacy Wagon/Forester got the 2.0T at 296hp, when it came to our shores, the power ratings were dropped for the varying fuel quality here. Japan apparently likes good, clean, high-octane fuel. 'Murica is a little sh!ttier in that regard.
If we're lucky, it'll come close to the Golf R's power output, but I would put money down (like, $0.50!) that it would not exceed it.
As for Honda investing more in the CR-Z? No chance. It'll be a Civic spawn only.