There's a lot of dread surrounding headgaskets.

Because of poor design (and how gravity works) the N/A EJ line suffered from predominantly exterior headgasket leaks until eventually the headgasket completely fails. Look at it as inevitable somewhere down the track

I wouldn't call burning oil a particular concern, do check whether it's also leaking into your spark plug wells though.

Do be anal about oil maintenance. If your car is burning a lot of it then top it up as needed, do new oil and a new filter approximately every 10k km (~6k miles). You may also want to run a slightly heavier oil still within your ambient temperature range but that's abit up for debate.

Apart from low oil easily killing a Subaru, It's a great habit to prolong your engines life.