You might be over-complicating things a bit.
Part of e17's effects are being covered up by the Nautilus file manger "desktop" running on Desktop 0,0. You can turn that off as described
here. Or just switch to one of the other Desktops (1,0 2,0 etc).
I have used some themes from:
http://www1.get-e.org/Themes/E17/
To use E17 themes, just copy them to ~/.e/e/themes and choose your favorite theme from the main E17 menu.
But like I mentioned before, not all of them work properly.
I don't think you need to install anything like xcompmgr on e17. Anyway, generally you'll see directions for using cvs or svn listed with the exact command you need to enter in a terminal window.
Like with Stella, the Atari 2600 emulator, for example:
http://sourceforge.net/cvs/?group_id=41847
You would do that if you wanted to download the latest source code in development, but usually for a stable release there are archives provided, as seen here (again with the Atari 2600 emulator):
http://stella.sourceforge.net/
stella-2.5-src.tar.gz Source tarball for all systems
If you get an error saying it can't find the cvs or svn command then you'll need to install it. If you checked Software Development (YDL6) during install you should already have them, I think.
In summary, you probably don't need to do any of that. Just try some of the themes from:
http://www1.get-e.org/Themes/E17/
I hope something in all this helps ...