Admins that only control a subset of users I am creating a page where users pay to create and edit their custom content.

These clients need to use multiple accounts with certain edit-rights - so they need their own people-management.

These are my requirements in that respect:


Each client-admin belongs to an organization that can have multiple members
Each organizatin "owns" certain content
Each client-user can edit content of his organization but only if the client-admin has granted him these rights


Is there a way that I can create admins that only control a subset of users?

(I found the https://drupal.org/project/administerusersbyrole module, but with that I would need a new role for each client. Is that a good solution? )
It looks like you're looking for Organic Groups.

[Organic Groups] Enable users to create and manage their own 'groups'. Each group can have subscribers, and maintains a group home page where subscribers communicate amongst themselves.
They do so by posting the usual node types: blog, story, page, etc. A block is shown on the group home page which facilitates these posts. The block also provides summary information about the group.
Groups may be selective or not. Selective groups require approval in order to become a member, or even invitation -only groups. There are lots of preferences to configure groups as you need.

It is a fairly complex module, but I think it is very well suited for your use-case.