Nobody was hurt, the next day it was business as usual. So give this kid a reasonable sentence for the damage done, and let him have a chance to see his error and learn from it. The lesson should be that he was lucky that this didn't turn into something really big. Next time his luck may change, and this experience may hold him back then. Send him to prison for seven years and he will come out as a wreck or as a professional criminal. Who wants that?
And we out here have zero idea of what his actual sentence will be. Yes, the max penalties for his felonies add up to 'years'. Will he actually get consecutive, max duration, penalty for each of them? Highly doubtful.
This, of course, depends on any past interaction with the legal system. If he is a repeat offender, then yes, he may well get the max. Otherwise, probably not.