Customizing Membership 2 Pro: Membership Access, Login Options

Hello,

We are using Membership 2 Pro to protect our website from non-members.

We want to control who can become a member. This website is only open to employees. We would like to manually add people and remove the option for anyone to "register".

1. Can we we customize the login form to match the colours and formatting of our site?

2. How can we remove the option to "register" on our login form?

3. Can we add multiple members at once?