This article is absolutely correct and I was actually only coming here to express my 100% agreement...
Right click the "down arrow" at the top right of each email you want to delete. Choose "delete this message". This will delete that particular email but not the entire conversation. Do that as many times as needed and voila.
could you elaborate more with what you want? What are you not wanting to make copies of? Multiple Filters/Labels can be attached to a single email without actually affecting the email directly.
See normally I would agree with you three by saying that organization is a good thing but Google totally screwed up.
@robotsneedhugs2, unfortunately it keeps a LOT more out than you think. If an email is sent to you and does not fit any of the "Google Approved" categories then you actually won't see it at all. If that happens, which it did to me often, then the only way to see it is to run the search "is:unread" in your email search...try it now, there is probably something there.
@Cambo I too like the idea of seperation but the Tabs are terrible because you don't get notified about new emails UNLESS it is in the Priority tab...some might like that but you have no control over what gets sent where so maybe I want updates about social networks or something...Google says "you dont know what you want". The tabs also suck when you are inside of gmail as they don't have an unread count next to the tab title like it should...so the only way to know if there is something there is to manually check it...and that is so freaking 1990s. Finally, this could easily be done with labels and the Quick Links lab feature. Enable the Quick Links lab, create a link to any page you want by navigating to the page and clicking "add link". Also if you use filters and labels you can have the automatic labeling done for you like the tab does but still get updated about it and see the unread count in the left sidebar.
@localhost it isnt the best but it easily could be if the tabs were controlled by the user and not Google...such as like @skottmorris suggested with the tabs being based on custom labels....which could be controlled automatically with filters.