Eurail Question? England and Czech Republic?

I know that neither England nor the Czech Republic are included in the Eurail system but when I look at the map of the routes, it shows a number of routes through England (and Scotland) and also through the Czech Republic. Are they just showing these routes to be informative or can I really travel through these countries with my Eurail P for free? Also, I have heard that Eurail pes do not cover the route from London to Paris (under the channel). How much would a ticket like this cost?