Going back to the Sam Raimi movies, he got it right. Kicked the movie off with Peter being in his senior year then moving on to the college which made it a bit easier for Peter to engage in his webslinging heroics. How are they going to justify Iron Man being in the movie? Is the Spider-Man movie taking place before Captain America: Civil War? Or after events of Civil War? It would be kind of odd to have an origin story taking place after the character has already appeared in a movie prior to the release of Spider-Man's solo movie.
I think if they went more closely with the Ultimate Comics approach to Spider-Man, it would have been better as far as him being younger and being an aspiring, but restricted, Avenger. Both Iron Man and Thor are blown away by how 'amazing' he is, though Cap is a bit more reserved about letting him on the team, and not just because of his age. Just gives him more incentive to prove himself, but not be such a damn kid about it. Yes, he's supposed to be mouthy but there's a fine line between clever and annoying and he was definitely on the wrong side of it for much of his time in Civil War.
At least when he's an adult, his day job allows him to do his webslinging with no restrictions since he just has to stash his camera somewhere and set it on auto and then just get to work. That then allows him to do his thing day or night. With teenage Parker, it's not as likely he'll be operating during 'business hours' as it were, at least if school is in session and not during a summer vacation or something.
I am looking forward to seeing the evolution of his costume, though. What looks like pajamas or a kid's Halloween costume is, hopefully, going to become more sleek and yet not lose that thing with the eyes where, like Deadpool, you can actually see him narrowing them or widening them when glaring or surprised. I just don't know whether I want him to ever get the Iron Spider armor, it'll take away from what makes Spider-Man different from the rest of the group. Although I definitely want him to get the alien symbiote costume at some point during the Infinity War movies.