Rpm issues

Hi and thank you in advance for any advise i get here!



I have a 320i 2000 170bhp with 122k on the clock... Ive just changed the alt and battery aswell as vcg and expantion tank.



My issue now is the other day my car would not crank at all starter wouldnt even tick happened for couple of goes and worked fine im assuming starter

Motor on its way out?



Second, on the same day when i tried to restart the car it would start rev up and then just die! Fuel pump kicks in fine any idea?



Third, while i am diving the car just dies with no stutter at all just died on me.



Also while idling my rpm sticks at 900-1000 doesnt got hunting but if i rev the engine up and let it drop it will stop at 1100rpm and then second later drop back to 900-1000 is this normal dnt sound it.



I have had the car on dignostics machine and MAF came up but issue is with this plugged in or not the car runs exactly the same.



The next was cam shaft sensor and mis fire cylinder six which i am sure will be coil pack.



I know thats alot but can someone please advise me.