[Ardour-Users] editing ardour session files

[sh0099]

i like to edit some ardour session files to be able to do things ardour 
is not able in the moment.
because of this i have a few questions.

what constitutes the order of tracks?

do i have to take care of the Regions->region->start time when i change 
the Playlist->Region->start time?
or why is there a duplication of time values in the session file?

thanks
olaf