How do I add and can there be multiple administrators?

Can there be more than one administrator with the ability to add and remove people? I need to get someone added or at least confirm why he does not have access currently.

By administrator I presume that you would like to give someone access to your forms with ability to change them and see the submissions.

This is possible by following the steps here: How to Share Forms with a Sub-Account User

You can decide if you want to give them the access to forms only or submissions only, or any combination of the two and set permissions per form, per folder and for entire account.

Now unfortunately there is not an option to have a sub account user to change your sub users (add or remove them) without you giving them the access to your own account, but they can share their own account with someone else and be able to administer them.