CY8CKIT-145-40XX kit comes with PSOC4000S device on it and also the Kit prog which is on board programmer and debugger.
1.The Buttons on the Kit as you can see are the mutual Cap based buttons, Therefore you can see one RX and TX pads connected to them.
2. The board has pins from the PSOC4000S device routes to the headers in the edges. You can connect these pins to your board which has buttons/sliders printed on them and use them for your design.
3.The kit prog implemented the USB-UART bridge which you can use and connect to the system for communication.