Is attending weekly confession a bad thing?

No, it is not a bad thing; you always receive the graces of God when you go to confession, and the Lord knows we all sin many times a day, sometimes very small sins. But confession was instituted because of mortal sin, since the only way a Catholic can be restored to the faith after mortal sin is through the confessional; you cannot simply confess a mortal sin to God and have it forgiven apart from the Church, because God works through the Church, even though He is the one who finally forgives it. For venial sin it is not so necessary. People who go to weekly confession are usually those very worried about their venial sins, and there is nothing wrong with that, but you can confess venial sins at home in the privacy of your room and receive just as much forgiveness; there is not less forgiveness because you confessed it at home.