How can I protect the account of the first user, and not allow administration users to alter it?
User Protect

From the project page:


  This module allows fine-grained access control of user administrators,
  by providing various editing protection for users. The protections can
  be specific to a user, or applied to all users in a role.
  
  Note: User Protect has a complicated configuration -- please take the
  time to read the very extensive module help before using it!
  
  The following protections are supported:
  
  
  username
  e-mail address
  password
  status changes
  roles 
  deletion 
  OpenID identities
  all edits (any accessed via user/X/edit)
  
  
  When a protection is enabled for a specified user (or the protection is enabled because
  the user belongs to a role that has the protection), it prevents the
  editing operation in question that anyone might try to perform on the
  user--unless an administrator who is permitted to bypass the
  protection is editing the specified user. The module will protect
  fields by disabling them at user/X/edit.
  
  User administrators may be configured to bypass specified protections,
  on either a global or per-administrator basis.
  
  These protections are valid both when trying to edit the user directly
  from their user/X/edit page, or using the mass user editing
  operations.
  
  The module also provides protection at the paths user/X/edit and
  user/X/delete, should anyone try to visit those paths directly.
  
  Note: this module is compatible with the RoleAssign module.