1.
Between the user and the LTM is the client side traffic.
Between the LTM and the server is the server-side traffic.
2. There are many reasons of why you would see Bytes out greater then Bytes in. One that comes to mind which is common is websites. When you enter say a URL http://www.something.com for example you are sending a request which is in kilobytes, but the response might be larger such as an image, streaming video, streaming audio. So the Bytes-in might be a request and Bytes-out is the webpage or music, video or images itself.
Hope that helps
CB