I am trying to use the AutoText toolbar in MS Outlook and have a few questions: 

1. Since I am using Word as my e-mail editor, the AutoText settings
are contained in the Normal.dot file. Is it somehow possible to just
transfer the AutoText settings to another PC without overwriting
custom settings already stored in Normal.dot on the other PC?

2. I created a bunch of custom AutoText entries and am now bothered by
all the ones that Microsoft provides. How do I take out the default
entries and just list my own?

I think this is what you're asking for.  Tested in Word 2003:

In Word go to Tools > Templates and Add-Ins > Organiser > Autotext

You can use this to delete the autotext entries you do not want in your .doc file

You can also use it to copy entries between templates, so you can take
a .doc with your custom entries around to all the computers and
transfer the entries across.

The .doc is stored in C:\Documents and Settings\user\Application
Data\Microsoft\Templates in case you don't know

Prawn's suggestion is true but a there is a file that stores the
autotext entries with an extension of .acl.  You can do a search on
the file extension and just move that file to any machine. 
Overwriting the one on that machine will automatically update your acl
(autocorrect listing) on that machine.  The suggestion prawn made is
correct in that we use this method to backup and print out cheat
sheets for acl's but moving the actual file to a machine is much
easier.  Also, in actuality autocorrect is one of the few things not
stored on the normal.dot but the fonts used are, so you should always
move both the acl and the normal.dot to get a smooth transition.  Hope
this helps.  KauaiDawn 1-888-464-3646 ext. 0414392

just to point out the obvious, i meant to say .dot rather than .doc in
my previous comment