Access rights on SQL Server 2012
GRANT ALTER ANY DATABASE TO [somelogin]; or adding the user to the db_creator server-level role, will allow that login to create and/or restore databases, however, that user will not be able to access that database unless the restored database already has a user with the same SID that has the appropriate access.  See my answer here for more details.

There is no server-level role or right that allows a login access to any database without simultaneously allowing that login to modify server-level properties.

The typical setup for creating/restoring databases consists of having a sysadmin member do the restore, and modify access per the requirements for that specific database.

Technet has a link to an excellent poster that describes all the rights and permissions grantable inside SQL Server.