Wrt work/life balance for teens -- as long as they don't have to prepare dinner or keep a house clean, I see nothing wrong with having them in school or involved in extra curricular activities or homework for most of their waking hours. This is how their university lives are going to be after all, and truth be told the early days of their careers are going to be work-dominated too.
DD1 did three sports over her four years in high school - badminton, swimming and water polo. First year -- badminton, second year badminton and swimming, third year swimming and water polo, fourth year same. The school year was divided into three sports seasons. Students could do only one sport per season. In order to stay on the active roster, students had to have at least a C average in their academic classes. Those who were failing a class had to go to academic table and get their grade up before becoming active again.
The following is a slice of DD1's daily life in a public (i.e. state) high school during her sport seasons.
5:45 arrive in school for practice
7:15 shower, dress, grab breakfast in the cafeteria
8:00 school day begins -- school includes daily PE
3:00 school over
3:15 afternoon practice begins
5:30 afternoon practice over -- if no game or meet scheduled go home
OR -- away game
3:15 board bus with team for away game/meet
9:30 - 10:00 arrive back in school on team bus
OR -- home game
3:15 practice while awaiting opponents' arrival
8:00 or 9:30 home, depending on sport (badminton and water polo early home, swimming late)
She did some homework on the bus and some between races and games, and finished the rest at home. She normally had about four hours of homework a night as well as study for tests. There was also homework on weekends. Most weeks there were at least two games/meets, and some weekends featured optional tournaments.
One year she did a school musical for a season where she didn't have a sport (plays and musicals were also organised on a three season basis).
Her coaches and the director of the musical were teachers, who were paid a nice stipend for their extra curricular contribution. These teachers were at the school from 5:30 am and didn't get home to their families until probably after 11 pm in their seasons.
DD1 also had a Saturday morning job from age 16 and did a lot of babysitting from age 13 on. What she never did, nor did any of my children, or in fact anyone we know, was hang around the streets with groups of friends in the evenings.
She went out a lot with friends and did plenty burning of the candle at both ends, but I let her arrange her own priorities. We always had late family dinners (after 7) and I saw her at groggy early breakfasts and schlepping her and her bleary eyed carpool group to early practice. She herself liked to spend time in her room making jewellery, watching box sets, and chatting on her phone when not busy.
All of my DCs had similar schedules, but DD1's is sort of burned into my brain as it introduced me to the world of HS athletics.