Oh and welcome to the forums too []
Oily and smokey - not good, and if they "could not be bothered" doing something, then I personally "would not be bothered" to buy it. There are LOADS of good examples out - keep looking and buy a good one.
High Mileage should not be a problem, as long as you pay less for it, and it has been meticulously well looked after. All cars can have problems but Impreza's seem to be as reliable as any Japanese car.
Brian