add-on images

I recently found http://www.novell.com/coolsolutions/appnote/11671.html
(AppNote: Sysprep, Add-on Images, Application Objects, Oh My!) and was
looking to do something very similar for our set-up here.

I just have a couple questions of anybody that is familiar and
comfortable with Add-On Images.

1) If my "Base" image is windows, novell client, zenworks client,
symantec, Microsoft Office, FireFox, iPrint, Finale Notepad, Adobe
Acrobat, and the whole muckload of brower-plugins (flash, shockwave
etc.) and windows updates (and of course sysprep) - Any time we need to
update any of those, we would need to image a machine with the base
image and the appropriate drivers add-on image, perform the update,
sysprep, and re-do the base image. is that correct?

2) If we have Application Add-On images, (say for ThunderBird) if there
is an update, we would take the base image, drivers add-on image, and
recreate the thunderbird image from scratch, correct?

3) How can I take different accounts into conideration? I.e. for some
computer we need to have personalized account that have administrator
rights, on others, we have global accounts, that are limited.

4) are there any "gotcha's" that I need to keep my eyes open for?

Thank You