In making a "highlights" movie, using clips from different imported iMovie events, can I delete the larger iMovie event file from the Events browser and still work w the smaller clips in the Projects browser w/o having the larger files still loaded?

Question

I have sucessfully imported 150 Sony digital 8mm movies (each one hour in length) into iMovie as 150 iMovie events. I have since successfully converted them from their original 13 Gb (.dv) file to an exported smaller 1.3 Gb (.4mv "large file") movie that I am happy with, using the iMovie projects browser. So now I have 150 " .4mv" movies on my internal HD as well as about half of my original raw data " .dv " movies on my internal hard drive.
Due to their large size (over 2 Tb), I do not have all the larger raw data (.dv) files on my 2Tb internal drive, just about half of them. What I want to do now is to create a new project in the Projects browser for each of my kids, and reload, starting with Tape #1, each of these larger files and do a highlights movie for each of my kids, wherein I pick out smaller clips from each 1 hour .dv iMovie event and paste them into the appropriate kid's Highlights project in the Projects browser.
Here's my question: If I load the first 5 large files back onto my internal HD, and paste in various shorter clips into each of my kids' Highlights project, and then if I delete those first 5 large files (they are backed up on 2 other 3Tb external HDs), can I keep doing this (reloading the next 5 large .dv files to work with), and ultimately take each of my kid's Highlights project and export as a .4mv movie EVEN THOUGH the earlier large .dv files are no longer on my internal HD, OR does my iMac need to have all these larger files loaded on my internal HD for me to eventually export each of my kid's Highlights project to a .4mv movie?
I have a 2011 era 27" iMac desktop w 2Tb HD internal and 250 Gb flash drive, and Lion OSX and iMovie 11.

Answer 1

Thanks. I tested it out and you were correct. I loaded 2 .dv movies from my external HD back onto my internal HD, and got them re-imported into iMovie, took a few short clips from each of the 2 iMovie events and pasted them into a new project in the Project Browser. Then I deleted these 2  "source clips" from my internal HD, closed iMovie and then re-opened it and found that iMovie would NOT export the smaller clips for a "highlights" .4mv movie without the "source clips" being available.
I read your link on Quicktime. It talks about mostly trimming, which is what I did with each iMovie event before I took each one as a project to export as a smaller .4mv file. But if I use Quicktime (do I need QT Pro or basic), what advantage is it to me to use QT over iMovie (I must admit I am a novice at iMovie and have never used QT or QT Pro as a tool)? Will it then convert any edits I make to a .m4v movie or do I need iMovie to do that?
Does QT allow trimming multiple segments out of a movie during one edit session, or can you only do 1 at a time? By that I mean that, for example, when I use Sonys Picture Motion Browser for my .mts movies, you can only set one Start and one End point for each edit/trim you do: it does not allow you to set multiple Start Stop points like iMovie allows in its Event or Project browser. You can only do one "trim" at a time, save it and then reopen to do another trim. not very useful.