Can you make Citra utilize more than one core?

So basically citra run at 35% speed most of the time so the implementation of multi core capabily would likely speed citra up a lot?

probably, right now there is no plans to implement multi core support since the focus is on compatibility and accuracy and implementing that would require a massive change in citra which is not a good idea since it might hide bugs or break a lot of things, you will probably have to wait a long time before getting multi core support