Remove the breather hose and direct it into a one gallon container and drive the car. If you've collected a lot of oil, you have a BB problem. If not, there is some other problem.

As Brian mentioned, bad valve guides could cause this, not so much by oil going down the valve guides, but by pressure escaping into the VC area, causing excessive blow-by. When the engine is under load, both the intake and exhaust are pressurized.

I would think the easiest way to check for the turbo leaking would be to idle the engine for a short time and then disconnect the engine pipe and see if there is an oil residue in the exhaust.

If the rings were your sole problem, you would have considerable difficulty in even getting this car started.