Yes, if a file has already been imported using step 1, then go to it in the
collection and split the clip into the parts you want... and you can
copy/paste a clip in a collection in order to get it into other collections.
You can also split, trim and copy clips that are already in a project.
I'm assuming that's what you are asking about. If I'm not thinking right
about your issue, can you re-phrase it?
PapaJohn