Compatibility
No. PS/2 mode is not supported
Yes. InputStick supports USB BOOT protocol for both keyboard and mouse interfaces.
Security
In theory no. InputStick uses encrypted Bluetooth connection and it is also possible to enable AES-128 encryption on protocol level (highly recommended).
You can restrict access to InputStick by enabling password protection (use InputStickUtility application). If password protection is not enabled then yes, anyone nearby can connect to your InputStick and use it to remotely control USB host.
No, keyboard or mouse actions are never stored by InputStick receiver.
No, InputStick works exactly like any other USB keyboard and as a result of that keyboard input can be intercepted by both hardware and software keyloggers.
Other
InputStick costs significantly more when compared to Bluetooth USB adapters. There are following reasons for that:
- more complex hardware (required to emulate keyboard and mouse)
- relatively low production volume
- retail price includes all taxes and international shipping cost
- you get free mobile apps and APIs
Note: it is possible to get significant discounts for volume/bulk purchases.