The Win32 memory manager was replaced in Delphi 2006 with one that is faster and more feature rich. This article is a summary of the new features and how to use them. It explains how the new memory manager was implemented, and how this new design affects the behaviour of the memory manager and consequently applications compiled with Delphi 2006.
http://bdn.borland.com/article/0%2C1410%2C33416%2C00.html
1b, 2a (mada je generalno svaki odgovor tačan, al ajde), 3 ne znam, 4a (4c su drajveri, tako da nije OS).
Mada bi mogli malo da apdejtuju ta pitanja od pre dvajes godina, u međuvremenu se pojavio i open source...