Will one who was disobedient to his parents enter Paradise, despite his abundant acts of worship, if his good deeds outweigh his bad ones? And does disobedience to parents invalidate good deeds?

Disobeying one's parents is one of the gravest major sins. The belief of Ahl al-Sunnah is that those who commit major sins are subject to Allah's will and will not remain eternally in Hellfire. The hadith "Three types of people Allah has forbidden Paradise for them" is authentic, and its interpretation is that they are either disbelievers if they deemed disobedience permissible, or they are temporarily prevented from entering Paradise for purification. As for the hadith "Three things no deed will benefit with them," it is very weak, and if it were authentic, its interpretation would be a temporary lack of benefit. The disobedient child is not judged like the polytheists; rather, he is threatened with the severest warning, as is the case for those who commit major sins.