Hi,
My son is a junior at a nationally known high school in New York City. He has a 91-92 unweighted average and a low 1400 on the SAT. He’s interested in cybersecurity and computer science but he’s also disorganized. He’s struggling to get higher than a mid 80s grade in AP computer science but otherwise has pretty good grades. Is a middling grade in AP computer science disqualifying if you want to major in comp sci.
No. That and his SAT will cull some schools from his list, but most of those would be long shots with spotless records.
Have him read How To Be A Straight A Student by Cal Newport this summer. It will change his life.
Nope - there’s all levels of schools - and he’ll find one to study whatever he wants - but it may be Hofstra instead of Harvard…but that’s ok.
Good luck.
Sometimes the school prestige doesn’t matter as much as other times. If your son wants to study the classics in undergrad but still work on Wall Street, then there are maybe 10 to 15 schools where he can pull that off without major family connections. If your son wants to get an undergraduate degree in CS and work at a good tech company, there are about 200 schools where he can pull that off.
Don’t worry too much about which college your child gets into if he or she is going into a STEM major. There are a lot of good CS programs out there that provide a good education and will be good enough for post-college job placement. The odds are pretty good that it will turn out well for the kid if they work hard.
I just ordered it. Thank you! 
Others have already said it, but your son should have many different options available to him to study computer science. Does he need any services with respect to the organizational bit? Is that part of a larger concern with executive function?