Dad and working with youth is great. Its quite easy to combine the two topics also.
So do you think the basketball idea is not the best one?
I'm worried about the dad topic because I don't want to accidently come off as whiny about it. I know many people have had it much worse, and both my parents never even knew their real fathers.
you can make basketball your main theme, talk about perseverance, hard work, working in groups, etc. It's a good way to show Ad coms who you really are. However, it's not a great biographical extension. I maybe biased cause I'm writing a PS from a biographical point of view, but I think it makes the essay a better read and if you do it right, your personal qualities will show.
Also, do not worry about being whiny, just make sure you show that you have overcome the misfortune. I know it's hard to know your readers, I was being anxious about writing my story and coming off as whiny, but I knew that the story would show important factors that contributed into making me, and try to turn it into a positive thing. I'm sure you can do the same.
Just concentrate on the essay being personal and interesting.