Standard boost is 0.7 BAR/0.8 BAR what you are running has been done for good reason most likely due to the new engine is my guess.

The fuel pump rewiring is done as the standard wiring can degrade due to it's age, building resistance and so you don't get the needed power at the pump. You want to actually be seeing alternator voltage at the pump WHEN under load, the fan OE wiring is also hopeless, even when new and needs checking/rewiring.

Even so you have a bigger turbo and other parts so even as it is at the moment I should think it's more than standard power around 2 BAR of boost should see the 380 mark, Impreza's are nothing special, so I don't see why everyone's piping up.

Even as standard there fast, it's just people compare to theirs which are tuned, so to them they would be slow.

Martin