A few days ago I had asked them if getting an air oil separator on my year (2012). Obviously I asked about idcs and let them know with my tune I was at 100-104% at 6000-6500 rpms. If I should get a cbe, if it was worth it as well as what type of oil they feel is best ( told them I and most here used rotella t6).
Yes, an AOS is a good idea on every Subaru motor regardless of the year. If you are asking about the injector duty cycle then it is fine... unless you want to spend money. You can get larger injectors but they will not give you more of anything but take away instead. You will lose fuel mileage and potentially some power. If you put on a larger turbo then you will need larger injectors.
A cat back on the 08 and up will not give you any more power just a different sound / look.
Motul is the best oil... hands down.