The drainplug has a copper washer, that's about the only copper in the whole car.

Rattling - probably heatshield on the exhaust manifold or the cat. My cat had a bad spot weld on the heat shield an it mad a terrible rattling. Maybe an exhaust hanger or something.

smoke might be valve stem seals or excess wear in the engine. I can tell you a completely rebuilt A15 is very reliable and doesn't use a lot of oil.