Unfold Preamble.
Extract stab.vim.
Extract register clearing.
Extract theme switcher.
Extract more stuff.
Remove unused configuration.
Extract more stuff.
Extract suffix_dependant autocommands.

Most of them landed in ftplugin, some in ftdetect.
Move rspec highlighting to plugin file.
Move "utilities" to plugin directory.
Move colorscheme settings to vimrc.
Extract hide_cursorline plugin.
Use spaces instead of tabs.
Don't use ~/.vimtags file.
Remove comments.
Assume colorcolumn is present.

I only use newer versions of Vim.
I don't use Vim in windows.
Move line to other file.
Remove redundant line.

Default setting for 'complete' is a superset of this.
Reorder lines.