So:
as jonesey suggested, start with track templates:
open source project
create track templates for each track, or set of tracks: this will save settings, routings,...
putting tracks into folders by type helps
select all tracks in folder and save as track template
open target project
drag/drop track templates: folders, buses, effects,... will be imported: no data
move to source project
copy clips and paste:
Select track number to hi-light clips, press control-c, check all that apply, click ok
move to target project and paste into correct tracks, at zero time