hello to the forum and why on earth would you purchase such a high mile car, bmw for that matter?
Your rpm is higher then normal, therefore fuel efficiency is gone. I don't understand the point i don't doing that for a dd.
At that mile you are bound to do plenty of refresh on the car. The front noise could be control arms (ball joints) or sway bar brushing. the front FCABs are bad once you notice wheel movement from side to side when braking from higher speed. It could possibly be strut mounts but i would check the sway bars bashing first and the control arms for play.
The rough idle could be vacuum leak. check the boots for cracks and leaks. it could also be ccv. If it was the injectors then it would idle rough from the start. Vanos will get loud in the front valve cover if the seals are bad.
these cars are very nice to drive but you must stay on top with the maintenance and preventive maintenance. If you are capable of working on cars, begin with a general tuneup, change all the oils, inspect all hoses and clean tb.
be prepared to spend a $1000 in parts in the first year.