RE: Disable sa account and rename
You can give GP users security to create new users and change passwords in GP. This will not give the ability to create new company databases or perform some functions in Professional Services Tools.
Add these roles to the target user within SQL Management Studio:
Fixed Server Role
SecurityAdmin
Database Roles in Dynamics and each company Database
db_AccessAdmin
db_SecurityAdmin
OR
Using SQL query
ALTER SERVER ROLE [SecurityAdmin]
ADD MEMBER [<GP User ID>]
USE [DYNAMICS];
ALTER ROLE [db_AccessAdmin]
ADD MEMBER [<GP User ID>];
ALTER ROLE [db_SecurityAdmin]
ADD MEMBER [ <GP User ID>];
USE [TWO];
ALTER ROLE [db_AccessAdmin]
ADD MEMBER [DYNSA];
ALTER ROLE [db_SecurityAdmin]
ADD MEMBER [ DYNSA];