For the vibrations, really try to rule out the exhaust system first. Had the same problem, no touching was visible while the car lifted but under running conditions vibrations became worse and worse. Replace if needed the two clamps on the exhaust between the catalyst and middle muffler. One spot you might consider looking at is where the two exhaust pipes go above the cross bar.
On the oil spill, take a look at the hydraulic pump. The transmission and front differential rarely leak on these cars but the hydraulic pump is at the right age for something like that. If you can look at the oil you might tell what type of oil is leaking - engine, transmission or hydraulic. Good luck.
