No. This application is not server-based. It is designed to be used offline and online; the application does not require an Internet connection in order to run properly. Regarding your second question, the keyboard application does have a Lock function, but it is locking its position on the screen. The application has a gadget right above the Windows clock that make it accessible faster.
"We want our user to get the keyboard pop up when we switch from one website (windows) and does not pop up on some others. Can this be done?" No. The application has an exception list to which you can add the programs for which you don't want the keyboard to be active, but you can't make the application to pop up when you switch to another window or program. For more information about the Comfort On-Screen Keyboard, you can visit the official website.