You probably allready got all the answers you asked for, and then some, but I'll chime in nevertheless.
By all means do a clean install with just the applications you'd like if you want too. Consider this however: You don't see any use for Garageband, iDVD etc. at the moment. However, let's consider the possibility that you use iPhoto to organise your pictures etc. Maybe som friends/relatives would like to have copies, better yet, maybe they'd like to have a neatly produced DVD with a slideshow as well as the original image-files included. Now if you remove iDVD you will have to reinstall it...
My point is simpy that while you can see no use for these applications at the moment there may come a time where they come in handy...
