Edit to add: WRT networking, it's kind of a suitcase word. Lots of people talk about it. I am sceptical that public speaking and improv classes are the best places to meet the best networking prospects, though they might be excellent for meeting interesting people. Athletes typically do better than the mean at Stanford-type schools in terms of career earnings, despite lower HS GPAs and test scores. If you're not currently a recruited athlete, you might still be able to walk on to the crew team or ultimate team.