The axle boot thing is pretty common, luckily my transmission was coming out anyway for a clutch job. Boost leaks will whine like that while/once spooled since they're now pushing air out. Your intake tract(turbo inlet, intake, etc) is constantly under vacuum so if leaks make sounds, it would always be there and just get louder.
I'm local if you need a second eye on something. Theres also a few others in the Austin area.