Thank you for your question.
1) Only Active employees count toward the total of employee licenses required, so yes, you can leave them in the system and all their time clock entries are retained when they are not active.
2) The Kiosk Solution is designed to be installed on one workstation at which all employees clock in/out. But you could install it in a shared folder on a network, open it on the workstation at which employees clock in/out. Then, when the client wants to administrate it, close it on that workstation and open it on Workstation A to administrate (it can only be open on one workstation at a time.) It's the most affordable solution and includes the FileMaker Runtime Application with the purchase. The Network Solution is installed, hosted and administrated on one workstation, but can be accessed via web browser from other client workstations (5 simultaneous / concurrent sessions). The purchase of a Network Solution includes the FileMaker Pro software and a license for one to install FileMaker Pro on one workstation to host and administrate TimeClock Pearl. Your client could install, host and administrate the time clock from Workstation A, but open it on Workstation B in a web browser for employees to clock in/out.
3) We're looking at both biometric and card readers for the next version of TimeClock Pearl, but no time table or final decisions have been made at this time.