Custom Application for clients

Custom Application for clients

Hi

I am trying to understand how we as developers are paid for the work we do developing an application that is privately published.

Here are the things I am trying to clarify:
1. Who owns the application we develop? The developer, the client, or Zoho?
2. What options do we have to charge the client? For example, does it have to be a one of development cost, or can we agree on a way of charging a client that can't pay for an application up front? Can we charge directly on a monthly basis, etc instead of publishing through Zoho Marketplace?
3. Does the developer have the discretion to remove client access to an application that has been shared from the developers account?

The scenario is about targetting a specific industry with a bespoke offering for taking bookings and appointments, only to certain operators in the industry, and instead of charging a lump sum, instead charging say a revenue share to cover development cost as their business uses the system. 

I would use Marketplace, but looks like we can only charge a fee per user, and that pricing model wouldn't work for what we are developing.

Thanks for all your help.