I'm looking for a list of the basics, for instance, not a list of all the plugins, but plugin would be on my list; here is what I have so far help me out if I've missed anything or if I've mis-named anything:
Vim has a user manual (:help usr_toc) that covers all of these topics. It's good to browse through in general and can be a good starting point when you're thinking How do I do X in Vim?. Opening up that help and doing a search is a good place to start.
Another important item for using the help is to get used to using the context-specific help -- :help help-context. Some help topics are ambiguous unless you include the proper context.
That being said, here are the sections about the specific topics you bring up.
:help vimrc-intro describes the basic info about where the vimrc lives and provides some example settings. Since the vimrc is just another vim script, the scripting section of the user manual (:help usr_41) is also useful.
These are covered in the scripting part of the manual mentioned above, but there are specific sections on using functions (:help 41.6) and defining functions (:help 41.7).
:help usr_27 describes searching and covers some regular expressions, but :help pattern.txt is the canonical section of the reference manual for all things related to Vim regular expressions
:help 40.1 covers all the high level details and :help key-mapping goes into all the nitty-gritty details.
The basic how of adding a plugin to your configuration is described at (:help 05.4) but typically people use a plugin manager to handle this now. Plugin managers provide, at a minimum, better isolation of plugins and the ability to easily enable/disable plugins.
Swap files provide a means of recovery, as described in :help usr_11. In a related answer, I've described this as well as ways to manage swap files.
Tab pages are basically viewports, or ways to organize windows. :help 08.9 gives a brief overview of what a tab page is, but :help tab-page gives more info on how to actually use them.
Split windows (:help 08.1) provide a way to view multiple buffers (or different views of the same buffer) at once. When Vim mentions a horizontal or vertical split, this is referring to the orientation of the actual line that splits two windows, not the orientation of the windows in reference to each other.
I think you're referring to the ranges automatically added to a command when you press : in visual mode (:'<,'>), however ranges can describe much more than just the visual selection.
:help 10.3 describes the general usage, but :help cmdilne-ranges has all the details.
:help 21.2 describes the various ways that external programs can be used -- directly executing one-off commands (:!), reading output from a command into the buffer (:r !{cmd}), sending the buffer to a command as in put (:w !{cmd}), and filtering a buffer through a program (:[range]!{cmd}).
The most comprehensive single-page reference is probably:
:help quickref
What you are looking for is usually called the vimdoc. An HTML version can be found here. It can also be accessed from within vim by entering :help.
For more information on a specific topic or key combination you would use :h pattern where pattern is the topic or key cord you are interested in. If you're not sure exactly what something is called you can use :h patt followed by CtrlD to get a list of topics that may match.
For a more detailed explanation on how to use help see this wiki.
:help. For an introduction / overview of Vim, there are tons of web pages, vimcasts.org, or even a number of books.