Developing secure, robust web applications in the cloud is hard, very hard. If you think it is easy, you are either a higher form of life or you have a painful awakening ahead of you.
Think twice before you launch your “proto-product”. Acknowledge that you are skipping many of critical security issues. At the very minimum, be honest with your potential users thar you are offering a prototype without full security.
This checklist is simple, and by no means complete.