When wheel bearings go bad (using non Subaru as reference) you typically get noise and eventually grinding, some play if really bad. Spinning wheel by hand should make noise and transmit a slight grind if failing. If on the highway and going around a long right/left-hand turn, it can make noise going one direction, and not the other, or be all the time, etc. Reason for the one way and not the other is it's loading the bearing on one side.
In/out play can also be a tie rod, ball joint, something loose with suspension, etc. With the tire raised, move it 12 and 6, 9 and 3, 10 and 4 etc. and look at the ball joint and everything else attached. Should be pretty clear to see whats moving. Auto Zone rents a small bearing press that can be operated with a ratchet. You leave a deposit and get the deposit with the tool returned (or keep the tool and they keep the deposit) so it's "free" to rent it. I've pressed bearings in/out with that and heavy duty 2 arm pulley pullers before (non Subaru). I just used a large socket or grabbed one of the sleeves from the press kit and used that with the pulley puller as alternative putting pressure on it in the same spot a press would) and had no issues. Just make sure it isn't crushing the sides or damaging the bearing. If in a pinch or low on money, this works.
I buy from rockauto all the time as parts for my Saab are typically 4 times the price of what a Subaru price would be for an equivalent part ($180 for 1 engine mount, $150-250+ for a fuel pump, $65+ for head gasket, etc.) and they're typically cheaper than O'Reilly's or Auto Zone even with cheapest shipping selected though it helps to order more than one thing to offset the cheaper shipping fee.