No problem - ask away we wont necessarily have relevant answers but there is always random mutterings instead ;)
As we dont know the history or how it was set up being modified from standard the 1.5bar could right... The larger turbo and extra plumbing of the FMIC could impact the spool up time which will give longer lag but a bigger punch when it comes in.
I would suggest a good service - plugs, oil and filter, check the air filter and brake pads & discs then you have a known starting point - I would then suggest a rolling road session to see what the current performance of the car is - not for power but to see what is working and where there needs to be focus.
for instance your injectors could need cleaning, petrol pump needs replacing etc
first thing though - you could share some photos - feel free to set up a new thread in the impreza section for your vehicle ;)