I'm an America developer that specializes in crypto and logical php applications systems. I know Perl, python, Javascript, node.js, and various other native languages. You can view some of my past work at https://wubur.com.
to answer some of your questions :
1. coinbase, for simple usage, and user flow
2. competition, and uniqueness. Everyone is doing altcoins now, but many of them are from inexperienced, underdeveloped platforms, often times planned by people who don't understand the industry.
3. Expecting to compete with bitcoin :)
4. This is a bit of a loaded question. If you mean from an exchange perspective, you simply approach them in ico, plan for every coin to make it, with a robust API system for the various wallets the coin creator is pronouncing with launch.
5. Another loaded question, as a developer, their should be no cross between liquid assets, including the customer base. From a storage perspective, i'd suggest having a unique patent-able offline storage system.
6. Various small wallets, but no exchanges. However, I do have very large projects from very large customers such as toys-r-us, and airBNB who would be more than happy to provide a glowing recommendation :)
Thanks!