Script to Deploy SQL Server Databases

I have an online Windows 2012 server with SQL Server. I would like to deploy a new SQL Server database to my customers. Each customer must only have access to their own database. I have started to script this (see below) but want an experienced SQL Server coder to improve on the security and ensure the script does the following: [1] Fix a problem - After creating the user and database, I cannot log into the database or create tables. If I use my sa account, it works so looks like a permissions / grants issue. [2] Allow me to specify Database Name, Username and password in one place such as a parameter at the top of the script so I don't need to find, copy and paste the values throughout the script. [3] Creates the database, the user and sets all the required security for the user to log into the database and create tables using my own custom software I have developed. The user must and have full access to the the database (to create and delete tables, SPs etc) [4] They must not have access to anything else other than their own database as there will be several users using the SQL Sever. I am sure this is a very quick job for someone and I will have a lot more SQL work for this project very soon and this will lead to a lot more work once i have found the right person. My original (not 100% working script): --=================================================== -- db_TestDatabase Database name -- TestPa$$w0rd password -- TestUser1 username use master go --create a test database CREATE DATABASE [db_TestDatabase] GO --create user login CREATE LOGIN [TestUser1] WITH PASSWORD=N'TestPa$$w0rd' GO --create user in database CREATE USER [TestUser1] FOR LOGIN [TestUser1] WITH DEFAULT_SCHEMA=[test_Schema] GO --create role CREATE ROLE [test_Role] AUTHORIZATION [dbo] GO --create schema CREATE SCHEMA [test_Schema] AUTHORIZATION [TestUser1] GO --apply permissions to schemas GRANT ALTER ON SCHEMA::[test_Schema] TO [test_Role] GO GRANT CONTROL ON SCHEMA::[test_Schema] TO [test_Role] GO GRANT SELECT ON SCHEMA::[test_Schema] TO [test_Role] GO GRANT DELETE ON SCHEMA::[dbo] TO [test_Role] GO GRANT INSERT ON SCHEMA::[dbo] TO [test_Role] GO GRANT SELECT ON SCHEMA::[dbo] TO [test_Role] GO GRANT UPDATE ON SCHEMA::[dbo] TO [test_Role] GO GRANT REFERENCES ON SCHEMA::[dbo] TO [test_Role] GO --ensure role membership is correct EXEC sp_addrolemember N'test_Role ', N'TestUser1' GO --allow users to create tables in test_Schema GRANT CREATE TABLE TO [test_Role] GO --Allow user to connect to database GRANT CONNECT TO [TestUser1] --===================================================