Buy or not? 2001 330xi 120k km

Hi all,
I am guest in here and will ask owners/mechanics about 2001 330xi 120k km which I found for reasonable price and package/color combination I like. It's grey metallic 5 sp. H/K, grey/blue leather sedan.
Car nice, one oner, records, but few thing looks suspicios to me.
1. Engine hesitates on idle more than I expect from 6 inline and compare to 2000 323i with 105k km which I drove week ago.
2. Loud sound from engine transferee through all body like you driving truck or small truck (so not been with 2000 323i as well)
3. Knocking sound from the engine , like bend valve or valves out of adjustment.
4. Car have double exhaust pipe but smoke (was normal grey) coming only from left pipe (looking from rear)
5. Car was long time on the lot around 5 month and brake rusted/bended.

I want to try ultimate driving experience but afraid of Ultimate Lemon and stories about Rocket maintanance prices. Also snow traction of regular RWD. Thats why I looking XI.

Please help me decide buy or not.

Big thank's in advance,
LX. :1zhelp:

knocking and bad idle, there's a chance the dumbass but 87 or something octane in it which isn't resistant enough for bimmer compression, smoke--was it cold? was it just started? what kind of maintainence? ask him how often and where he get his oil changed and what weight, maintainence and how it was treated is 100% of the life of the car, I've seen 50k mi beamers break down, mine has 250k and drives better than a brand new acura i used to have. The owner makes all the diff.

knocking and bad idle, there's a chance the dumbass but 87 or something octane in it which isn't resistant enough for bimmer compression,

[B]
smoke--was it cold? was it just started?
Yes, grey normal smoke for 10C 80% air humidity, when car just started.

what kind of maintainence?

see above.

ask him how often and where he get his oil changed and what weight, maintainence and how it was treated is 100% of the life of the car, I've seen 50k mi beamers break down,

I've seen what dealer show (records) an told me. Car was puchaised from auction dec 2003. This is not privet sale.

mine has 250k and drives better than a brand new acura i used to have. The owner makes all the diff.

I have Accord 98 coupe, many people saing it drives like new Honda, but strange suspension, engine noise (high rev.), and "normal" oil consumption (1L at 1500 km) pest me off....

Sorry,

I has delete some words.
The cars service book has records just at 55k, 82k, and 106k.
Others missing. Salesman at delership said it were just oil changes and usually not recorded??...