Theres no way to test engine condition. No inspection or even pulling the engine can verify lower end bearing condition. Anyone that says otherwise is selling you something.
1. Ask how long the head gasket repair warranty is on the vehicle and get it in writing. Standard shop warranty is 12 months, 12,000 miles if you have it done anywhere else.
Cut the oil filter open and check for debris and send in oil samples to a UOA joint. That’s all that can be done and an inspector isn’t going to do it.
Its highly dependent on how badly you need a car and how much you’re willing to wait.
It’s risky like any used car purchase. If you want to maximize chances pass on any car until you find a compelling reason to buy. This one doesn’t sound great unless you get better feedback on the repair, history and timing components.
That car needs $400-$800 in timing belt work before I’d recommend going in debt over it....in addition to properly installed head gasket.
If you get the sense the mechanic use Subaru gaskets and properly cleaned and bolts properly torqued and new timing kit - buy it. Brakes and everything else are easy relatively speaking, it’s not that worrisome for anywhere to do those.
A head job is far more technical and hinges on proper cleanliness, prep, and attention to detail more than just about any other work. How do you feel about this shop doing that? If not, move on until you find one.
Any 2010 under a loan needs a new timing kit or at a minimum the timing belt and lower timing pulley IMO.