Cant edit schema or data from sql server management studio
Not that I am using SSMS 2012, but in 2008 R2 is generally the same. There is no GUI for neither table designer, nor "Edit top 200 records". You have to begin diving into the DDL and DML for SQL Server and give up GUIs. One way you could use GUI to some extend, especially for DDL is to use the portal provided Windows Azure SQL Database manager. You can find a link to it when you go to your database from either the new or the old portal (Manage). Other way is to use some third party tool, which I am not aware of.Here is the link to that manager from the new portal:
Another option some people may find helpful, if you have and use Visual Studio then you can link to the server in ServerManager, connect to the database, and then design and edit data directly. 
My 2008 R2 version of SSMS had the same problem. I downloaded 2016 CTP3 SSMS which has Azure support and everything is normal for the Azure Databases.
https://msdn.microsoft.com/en-us/library/mt238290.aspx
I did lose my connection history information so beware.