Fixed Recurring Invoices With Variable Time

Fixed Recurring Invoices With Variable Time

One of our services is a monthly Pay-Per-Click service where we charge our Customers the same amount of money at the beginning of each month. We have a project for each Customer in Zoho Projects where we track our tasks/time. While the amount we charge is a constant, the amount of work we do fluctuates from month to month. 

I'm thinking that we should use Recurring Invoices and associate the Project from Zoho Projects. 

Questions:
  1. If we associate the project from Zoho Projects to the recurring invoice, will we be able to invoice the same fixed amount regardless of amount of hours logged?

  2. Will these recurring invoices show up in the Finance tab in Zoho Projects?

  3. How can we see a Report of dollars invoices VS amount of time worked? (Might this require a custom report?)
Thanks,

Scott