Q: Need Extra-Ordinary ways to Clear space on HD

Months ago I posted twice about problem clearing space on my MBA. Problem is back, and I still have same questions.

First I asked about deleting iMovies, b/c it takes up 4.15 GB and I have no movies. https://discussions.apple.com/thread/7057523. The responses directed me to take other steps, but didn’t answer whether I could delete iMovie.

Next I asked about the 19 GB that were unaccounted for or unexplained in the User folder. https://discussions.apple.com/thread/7057523.  the sum of the folders in User were about 2 GB, but the folder has 21.5 GB.

I don’t have any music, videos, or any large photos. my iPhoto library is only 1.5 GB of photos I want to carry on the road. Trash is empty, as is iPhoto and Mail trash.

The only recommendation I have not follow is to remove “unneeded emails.” How do you know what’s unneeded until years later when you need it. I only have a 2 years mail on MBA; all mail is archive on an iMac via TM. I delete-empty all unimportant emails, and deleted-emptied all junk mail. All those steps cleared a couple hundred MB of space.

I don’t see any other ways to clear space. In Applications I have 2 iMovie apps, 9.09 (1.2GB) and 10.0.5 (2.95). Don’t use either, and removing iMovie still appears the easiest available way to clear space.

I’m back to where I started. Why not dump iMovie apps and trying to clear out unexplained space in User folder.

Thanks for any other suggestions.