Wandering in the Wilderness Project

I recently became fascinated with Ruby.  I am starting a personal 
project to learn ruby from the inside out. I think it is the only way to 
fully understand a language that is this subtle!  Toward the end, as I 
read the documentation (ie THE SOURCE CODE!) I run into things that seem 
to have more aspects to them than is apparent, or I just don't 
understand the reason why they exist.

The questions I will be asking fall into three (for now) categories
   1) WHY something was done  this way
   2) WHAT am I missing?
   3) DO I have it right?

I intend to compile the answers to these questions into a FAQ at some 
point.  Any help given would be appreciated.

==========================================================================================
                       R U B Y - C O R E   Q U E S T I O N S   
==========================================================================================

0) Memory is always allocated in Quad Byte! 
   (Seems the basis of VALUE Interpretation)

1) VALUE Interpretation - Is the following Correct?

  a) If the LSB = 1, it is a Small Integer. 

  b) If the VALUE is equal to 0,2,4, or 6 it is a special
     constant: false, true, nil, or undef. 

  c) If the lower 8 bits are equal to'0xe', it is a Symbol.

  d) Otherwise, it is an Object Reference 


2) 'special_generic_ivar' - Is this to trigger Garbage Collection ONLY                
                            only for Special Constant Values?
                          - If it is - Is it because there is no real
                            object in Object Space to trigger GC?

3) Question - Why not put 'iv_tbl' pointers in all Built-in Objects.
   
   a) Can every Object have valid Instance Variables?

   b) Ruby Hacking Guide seems to put forth the argument that 'iv_tbl' 
      entries in other Built-in Objects would waste to much memory.
      
        aa) Why? -Four bytes per object does not seem to be a major hit?
        bb) Even if it is - Memory Usage should not be a problem for the
            scale of programs using Ruby - Or am I wrong?
        cc) Memory is cheap and getting cheaper all time - Even at home
            512K is under $45.00(US). 
        dd) I would trade reasonable increases in memory usage for               
            greater processing efficiency EVERY TIME!
 
-- 
GodFather -- 667 Neighbor of the Beast