firstly, what is the reason for the downgrade?
check you're using osx.4.7. have all updates for that installed, including pro app support.
anything that uses features exclusive to 7.2.1., will obviously not be present in the earliers versions, so you could get small "bugginess".
go to receipts in the main library and rip out the ones for logic.
go to user/pref/logic and rip out what you don't think you'll need.
save to cd/dvd all your user/unique settings. (generally in the app sup and audio folder in users and main.
rip out logic and wb apps, etc.
you may leave all the exs24 samples,etc.
it's a dirrty job, but somebody's got to do it.
