Vim

multiple buffers and tabs

Why not use tabs (introduced in Vim 7)? You can switch between tabs with :tabn and :tabp, With :tabe <filepath> you can add a new tab; and with a regular :q or :wq you close a tab. If you map :tabn and :tabp to your F7/F8 keys you can easily switch between files.

syntax highlight

:set syntax=html

find and replace

:%s/foo/bar/g

case insensitive search

You can use the \c escape sequence anywhere in the pattern. For example:

/\ccopyright or /copyright\c or even /copyri\cght