Welcome to the club. I'd have been dead chuffed with an impreza as a first car. My partner has an 1800 non turbo classic and she is still on L plates. Although we are slightly older.
As a first car it may be quite large and daunting when it comes to tighter corners on any parking manoeuvre. Have you checked the insurance on a wrx? That will be your biggest hurdle. You could consider a gx/sport(not sure what they're called on blobs) scoop and spoiler and it'd look the same.
Welcome to the club. I pulled the same trick "5 door family car"
There are plenty of events throughout the country all through the year. Pop in to the event section and have a nosey [emoji4]
Oh, and Chuck up some pics for us [emoji106] [emoji4]
Just a thought and have no idea if it would work. Could the fmic be installed but leave out the top parts of pipework until remap? That way you can still run with the tmic. For the impatient for fitting amongst us [emoji15]