Welcome in the forum!
Yes, you can use a KitProg as a stand-alone programming and debugging platform. The only downgrade when snapping it off : you are breaking two internal connections between UART Rx/Tx to the Kitprog which are used for a USB-UART bridge. You can re-connect those two lines when at need using the board/KitProg connectors.
You may get the source code from Cypress at request. At top of this page "Design Support -> Create a Support Case"
The information you need (documentation, schematics, examples...) are installed on your PC already when you installed the Prototype Kit's files from here. Search on your computer under C:\Programs (x86)\Cypress. You will find entries for every Kit you installed. The schematics are located under the Hardware-folder as PDFs.