I got to know the numbers plugin from http://vim.spf13.com/
This distribution gets you a really good head start on vim and lets you install additional plugins easily with its VBundle Integration and its customization options.
And in case if you ever wondered, why the ESC key is used to change to normal mode, you should read up on the history of the escape key. Therefore I use CTRL-<P> to switch to normal mode, so my hands can stay on the keyboard.
No. SPF13 and the other so called "distributions" are the worst things a new vimmer could install. Starting with vanilla Vim is the only sane option if you are serious about it: learn the basics, get used to them and, if you don't like them, create your own mappings and/or look for plugins.
Be a Vim user, not an SPF13 user.
Also, you don't need to remap <Esc> to <C-p> as there's already <C-[> or (the slightly different) <C-c>.
And in case if you ever wondered, why the ESC key is used to change to normal mode, you should read up on the history of the escape key. Therefore I use CTRL-<P> to switch to normal mode, so my hands can stay on the keyboard.