1) Usually, defragment
your Hard Drive first though.
2) either or. Mepis is Ubuntu based and carries many of the same packages.
Beryl is not a GUI (you will need Gnome or KDE) it is a Window Composting Manager (i think thats right, dont hold me to that term) anyway its like Aero in Vista from what Im told (I dont have Vista) where you can disable it or enable it.
The repositories. (System->Administration->Synaptic Package manager, in Ubuntu 7.04 with Gnome)
4) CDs are plenty for either distro (both will run as a LiveCD so you can try out which one you want to use before installing). Side note:
Ubuntu Studio requires a DVD
Beryl is a derivative of Compiz (which comes with the the install of Ubuntu under System->Preferences-> Desktop Effects) and from what the little internet birdies tell me (rumor) Compiz and Beryl are reuniting to form Compiz-Fusion.
Edited by BlackSpyder, 31 August 2007 - 04:18 PM.