Okay, I found these brilliant & informative links online, as to how Lion installer & multiple installations, works:
http://www.tedlandau.com/slantedviewpoint/index.php/archives/2011/663
http://netkas.org/?p=619
These links may well contain incorrect info, but they sound like they make sense, based on my knowledge of disks, installers and partitioning.
http://www.tedlandau.com/slantedviewpoint/index.php/archives/2011/663
http://netkas.org/?p=619
These links may well contain incorrect info, but they sound like they make sense, based on my knowledge of disks, installers and partitioning.