Have you seen the "What are the most popular services used by Y Combinator startups?" infographics? Mixpanel seems to be doing extremely well among YC startups.
I voted for Ruby and JavaScript because that's what I use. I've tried some Python/Django but it somehow didn't feel right. I guess it really comes down to your personal preferences.
I would definitely recommend learning the basics of some programming language. If anything else this will help you to understand what's going on and what needs to be done to have your vision implemented.
What if I want to use CDN to host images? Maybe I've missed something but I could only find an option to Upload images.