Will a servant enter Paradise if his good deeds outweigh his bad deeds, and will he be held accountable for his bad deeds in this case?

Yes, whoever's good deeds outweigh their bad deeds will enter Paradise, as Allah Almighty says: "So as for he whose scales are heavy [with good deeds], He will be in a pleasing life." As for being held accountable for their bad deeds, there is a difference of opinion among scholars on this matter.