The problem with CasparCG is, that, while it is very power full, it is more of a developer, than an end-user product. CasparCG consist of two pieces of software:
the server, that render everything and sends the output to SDI, NDI etc. And the “client”, a user interface, that controls, what the server does. This client software connects to the server via TCP/IP and controls it sending text commands to it.
Compared to a standard CG (like the mentioned Titler Live) you do not get an editor to create your graphics and play them out from there. Instead Caspar uses templates, created in HTML (or Flash). Currently there is no point and click way to create these. You need to build them, like any other website, more or less from scratch.
With your use case there are two things, that needs to be solved: First you need to have a way to read the XML data and send it to Caspar. This would be a custom client and would be built in a programming environment. Then you would need a bunch of templates to display the data.
So I guess a step by step guide to do all this would be too much to write in a forum post. But there are all sorts of helps to create templates around the forum, on GitHub and YouTube etc.
To play around with Caspar you can download it from the build site or GitHub. There is also a standard client, that let you play stuff, but it does not allow any data connections or the like, just manual control.