As for the second question, what advice would you give a 25 year old you?
Stay the course, but be sure to have interests and hobbies that don't involve sitting in front of a computer. I wouldn't change anything about my career trajectory. I'm glad I spent four years in a huge corporation, and I'm glad that I've had the opportunity to work in (and create) companies of all different sizes subsequently.
It's not even a regret, per se, but I wish I'd gotten more serious about photography in/around 2007 instead of dithering for another six years.