Hi guys, I hope you can help me. I'm aware that this is not an Apple specific forum, but I guess that Macs are becoming more popular for video editing these days, so I think that for obvious reasons you may be well qualified to answer this question for me.

I don't take to computers naturally, and just when I was starting to get slightly used to a PC..... I bought a Mac, and it mostly still is rather alien !

my rough process (so far as I can remember it correctly) :

create a folder on Desktop for my particular project, I drop the content of my camera's card here (see Q1 below)
typically, my photos are (currently) from iPhone, so those stay in Photos folder
I drag and drop from Photos and find the appropriate footage to import into iMovie 'My media' (see Q2 below)
I edit my movie (think it's called a 'project' ?) and when finished, I click 'Share' and save it as a file, it goes to Downloads (see Q3)
I can pick up this completed movie, from Downloads/Films and drop into Youtube, all good
Left behind in iMovie is the 'Project' see Q4

however..... my computer has files all over the place, and I feel I would be more comfortable with these on an external drive, so :

Q1, can I drop all my footage straight to an external drive (where it'll stay for storage when my SD is deleted) ?

Q2, the media that I drop into 'My Media' in iMovie, is that a separate instance of the media, can it be deleted from Imovie when work on that video if finished ? (and I won't lose the original files?)

Q3, I'm guessing that this completed Movie in Downloads is indeed it's own separate complete file, such that I would probably want to move the location of my Downloads folder onto that same external drive ?

Q4, In Imovie, I'm collecting these completed 'Projects', can they be deleted after they've been uploaded ? after all, it's only the same as that which was 'shared' to 'file' and saved in 'downloads' ? ...... or is it kept in iMovie because it's in a format ready for further editing ?

if you can shed any light on this, it would be most appreciated

many thanks for reading