Purchase advice: V50 T5 with almost 300,000km

Hello, after the sudden injector death of our Ford Mondeo I am looking for a combination. I had originally thought of gasoline engines, because the annual run performance will probably not exceed 14tkm and will also be a rather high short distance share (<10km). I came across the Volvo V50. In my vicinity one with the T5 (220 hp, MY 2004) is running with something over 280tkm, automatic (edit: gearronic, oil change unknown). Two topics concern me concretely: First I have seen sooty (?) residues in the oil cover. Oil sludge is not known to me specifically as Volvo problem but can someone tell me what to the picture in the annex? Normal? Fingers away? Second: Topic AHK. What trailer load can the V50 pull with the engine? The all-knowing Internet speaks of 1500kg but that seems to me quite little... Then I also like to hear some of the emotions of the magazine.