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.
Move back misc options into vimrc.

Also add fold for block of sourced files.