2002 BMW 525i engine light on

Just bought this 525 I 2002 with lots of hidden problems. First it burns oil. Did the compression test. Cyl1 180, cyl2 175 cyl 3 160, cyl 4 165, vyl 5 170, cyl 6 125! I did engine flush with bavauto recommended lubro moly. It looks like it stopped blue smoke from puffin but is still consumes oil. I never replaced the oil separator and hoses around it. Mechanic told me that they were fine but I read that at this milage it has to be done, period. Now I did the ligh engine check and it said something about, post catalyst fuel trim bank1 1 too lean, and some misfire 1, and something about fuel low. I had also fuel injectors cleaned when I bought is and valve cover gasket replaced, and spark plugs replaced. Please tell what are my options, thank you