Sorry, we seem to be talking about different problems. I am speaking about, when importing new sequences, the creation of duplicate media. Your interaction on twitter is about deleting media and not having it be removed from sequences. The duplicate media issue was fixed in Premiere CC 2014 - when you import, you are asked if you want to create duplicate clips.
If it's loading time you're worried about, I would be skeptical that deleting a clip from the project but not a timeline would speed load - the program still has to load the file because you're referencing it in the timeline.
If you really want better loading times, go Avid, dude, and use some bins.
R