it is not intended to be a standalone addon. its entire purpose is to provide library loading functions so you don't have to have a standalone library loader like acelibrary. no, you should never move it out of a library unless you're embedding that library and you know what you're doing.
But to answer your question, yes, you can delete it from all your addons, as long as at least one addon loads it before any addon needs it. It's versioned like any other library and registers the "LibStub" variable in the global name space so anyone can access is directly as soon as it has been loaded once.
By deleting it from all your addons, you'll get a prolonged load-time. This is because every time an addon loads, it will try to load the libstub.lua file, but because the file does not exist, it will have to write a log entry with the error. For some reason, this takes a long time (blame Blizzard for that one). This is why disembedding libraries in general makes the load-time longer, *unless* you also update all the TOC and/or XML files to not try to include disembedded libraries. Some have made scripts for this, but in my opinion, disembedding is like pissing in your pants - you might save some load time (if done right), but the time spend solving collateral problems will often exceed it by far.
Haha. Colorfol analogy, but inaccurate IMO. Any decent updater (I use JWU) can automatically remove embeds and comment out nonexistent file references. Plus, I was under the impression that nonexistent file references only increased loading time if they were in the .toc, which was the reason for creating the embeds.xml file.
But with regard to LibStub, it is not intended to be run as an addon, and unless you want to manually edit the Dependencies .toc field of all your libraries which need LibStub, you can't run it as an addon. Leaving it present in Ace3 is also insufficient, as there's no guarantee that Ace3 will be loaded before any other libraries which need LibStub (although usually it will be, on a filesystem that loads in alphabetical order).
Well, if I use Windows Vista and have Libstub in Ace3, can I remove it from some of the folders it's present in? It's mainly present in just libraries and like I said, I'm OC about it and would like to remove it if possible.
I deleted your post xbeeps because it is moronic and completely unsupported. Don't fiddle with LibSub, end of story. You're not going to see any decrease in load time at all because it is simply too small. Leave it as it is.