compression test at 1st set got poor result but reached to benchmark at second set

i am recently done with compression test from a chinese mechanic who seems have problem explaining that i would like to know. i have bought this car recently from dealership shop . however price was low which aroused suspicion . compression test result for engine was 160.160.120.160. at third cylinder for 1st set of 5 crank resulted poorly 120 . nevertheless, mechanic told me that he would be doing it again . it got up to 160.160. 140.160 psi at second set of crank. i was suggested that engine is okey at this moment . while asked for further leak down test, he was unhappy and told me the car is okey to drive .my question is 1. it seems at this point that the car is okey to drive but i would like know driving softly will prolong its life any longer .2 should it be good idea to drive at120 kph or i should stick to only city driving with soft acceleration .3. 140000 on its clock reading, how long i can expect to drive before breakdown happens .using full synthetic engine oil