File Icons & Associations confusion

I just cannot seem to grasp the concept of icons and file associations under
Tiger. Here are my experiences.

I have 3 basic text editors installed.

TextEdit
Taco HTML Edit
Smultron

In each program I create and save a simple .txt file, naming each one the
same as the app it came from. The results are as follows

textedit.txt (blank icon, opens with Taco)
taco.txt (blank icon, opens with Taco)
smultron.txt (smultron icon, opens with Taco)

Now, all these files open with Taco because previously I did a "change all"
on a txt file so that all .txt files open with Taco. That makes sense. The
*reason* why the icons are all different is something I cannot grasp.

If I look inside the TextEdit.app package eventually I get to this icon file
" /Applications/TextEdit.app/Contents/Resources/txt.icns " & "
/Applications/TextEdit.app/Contents/info.plist " contains the reference to
that icon file, associating it with ".txt" and ".text" extensions. So this
means, if I change .txt files so that they all open with TextEdit, all my
.txt files will be given the icon that is contained within the TextEdit
Application for txt and text files. However, if this is the case with
TextEdit, then why above does my "smultron.txt" file have a smultron icon?
surely if it does then the .txt file created with TextEdit should also have
an icon, the "txt.icns" as described above?

If I do another "change all" so that all .txt files now open with TextEdit,
after a finder relaunch(why do I gotta relaunch all the time?) all three
icons change to txt.icns TextEdit Icons and all open with Text Edit. Now, if
I save the same 3 files again. Here's what I get.

textedit.txt (txtEdit icon, opens with TextEdit)
taco.txt (txtEdit icon, opens with TextEdit)
smultron.txt (txtEdit icon, opens with TextEdit)

OK, now this is better. But if I go back and "Change All" again so that all
.txt files open with Taco", after another finder relaunch I see my icons
have gone back to the way they were to start with, ie, every icon is blank
except smultron.txt

Anyone willing to try and explain what exactly is going on? please...?

-------------

This brings me onto another point. I have Both "Pages" & "TextEdit" on my
system that I use to create Word documents, (.doc). Both these programs
don't have an icon associated with word documents, so everytime I save a
.doc file from either program I get a blank icon, unless I have a program on
my system that is the default app for .doc files such as MS Word, which
obviously will mean word files have an icon, but I don't have word, so I'm
stuck with blank icons.

If I want to assign an icon to .doc files I have to go into the pages or
textedit package, edit the "info.plist" file and create my "word-doc.icns"
file, as described here
http://www.macosxhints.com/article.php?story=20040809000710242

I could have a hundred different apps that I use to open word docs, is there
not a better way to assign a system wide icon for .doc files rather than
ther application specific method above?

regards

Question,...

before you did a "change all" were there three icons for three programs?

if yes,..

I believe there's a prebinding database that stores this info. perhaps removing either the entries for the taco and smultron apps along with deleting the pref files for those apps will bring you back to the beginning. pre "change all" state. It really depends on the app author to give you results that you expect. It seems the text edit app behaves correctly, yet the other two were poorly written.