IDK about you but I can touch the cool side of my turbo after driving the car and its just a little warm, that is what your air is passing through, then it gets compressed, and that causes the air to heat up, which is why we have an intercooler. I do agree that the consensus is the stock air box's airflow rate is good enough for up to 400whp builds, thats been the consensus for a long time.
OP, as long as you are tuned for it, there is no issue getting a intake if that is what you want to do with your car, as mentioned, BOV's do cause issues and are best to stay away from unless you get a blow through pipe with a front mount intercooler set up, or a speed density setup. A intake will get you that pssht sound from the stock BPV if you like that sound. I don't know how you want to build your car, but going stage 2, opening up the exhaust to hear that subaru rumble, and working on suspension will make your car an absolute blast to drive while keeping it reasonably reliable.
With these cars you really need to do a lot of research for each mod you want to do.