Hi Shinzo,
Martin has provided useful and detailed information. You may refer to that.
About SharePoint development, I have included some links for you that may be helpful, including the features available to developers for Office 365. Microsoft does provide custom solution and development support, however there may be a consulting fee associated.
You may also want to post your question to the MSDN forums for a better response for custom solutions.
Here are the links for your reference:
http://msdn.microsoft.com/en-us/library/ie/gg454740.aspx
http://msdn.microsoft.com/en-us/library/hh147180.aspx
@Martin, we appreciate your efforts.
Thanks,
Kevin Cui