Q: How does one go about customising the LCCS components or pods?
All the pods are in a way implement the MVC framework. So the WhiteBoard has SharedWBModel and you can always use the model and add your own functionalities and have a custom UI. UI customization can also be done as the SharedWhiteBoard extends UIComponent. Please refer to WhiteBoardCustomShapes and CollabPicViewer in SDK's sampleApps to customize whiteBoard.
Similary the WebCam has WebCamPublisher and WebCamSubscriber components. Both the components provide you the flexibility to customize WebCam
Similarly explore SimpleChat and SimpleChatModel for messaging.
Can you give me a sample for the Simple Chat customization, for example: Border, Message input Text height, sendButton customization?