RE: oil filters. Stay with Subaru OEM oil filters. These cars don't like any aftermarket ones.
Oil is a touchy subject (as usual), but Mobil 1 is fine if you're not pushing the car ridiculously hard. I read somewhere on NASIOC that Rotella T6 is pretty good too, but they're using a different weight than Subaru specifies for some odd reason. HAven't figured that out yet.
I'm using Royal Purp because I have Pep Boys coupons