Any kid that's smart enough with chemistry to design his own
webshooters that shoot webs that don't need to be refilled
every five minutes ---and can hold up cars, etc.
can feasibly do ANYthing--- a suit'd be a snap.
THERE's your answer 
(Heck, he probably coulda designed and built time machines if he wanted to)
Now in the movies they smartly circumvented the whole idea
of "irrationally great web scientist" by making his webs organic---
so---um---in the movies, I have no idea how he was capable enough
to make his Spidersuit
When I .... how do you say (?) .... think of my mindframe on this spaceplane, I'm Skywalker with my X-Wing like I was when I was a kid.