Get NERDTreeTabs behavior, without the tabs

vim_buftab_nerdtree.vim

" https://github.com/jistr/vim-nerdtree-tabs

" display list of buffers like tabs
Plugin 'ap/vim-buftabline'

" claims to solve w/wq edge cases and I believe them
Plugin 'mhinz/vim-sayonara'

" automatically enter/exit paste on inhuman input speed
" added because paste disables abbreviations,
" unsure how important it is yet
Plugin 'roxma/vim-paste-easy'

" Returns the first window ID containing a file buffer
"
" Iterates through window numbers until the last (winnr('$')),
" Skipping special buffer types & preview windows
function! FirstFileWindowID()
    let i = 1
    while i <= winnr('$')
        let bnum = winbufnr(i)
        if bnum !=# -1 && getbufvar(bnum, '&buftype') ==# ''
                    \ && !getwinvar(i, '&previewwindow')
            " TODO I don't know what excluding &hidden does in the original,
            " but may be desirable for correctness
            return win_getid(i)
        endif
        let i += 1
    endwhile
    return -1
endfunction

"tab movement (ctrl-n for next tab, ctrl-p for previous)
map <c-n> :call win_execute(FirstFileWindowID(), 'bnext')<CR>
map <c-p> :call win_execute(FirstFileWindowID(), 'bprev')<CR>

" tab-like :q behavior for buffers
" Prevent accidental closing of all buffers when doing :wq or :q
cnoreabbrev wq w<bar>Sayonara
cnoreabbrev q Sayonara

" make sure paste doesn't disable abbreviations,
" breaking the above
set nopaste

" TODO haven't gotten around to it yet, but should probably munge
" keybindings a bit regain the ability to replace current buffer
" change o to t as regular opening is now
" like open-in-tab behavior
" let NERDTreeMapOpenInTab='\t'
" let NERDTreeMapActivateNode='t'

FirstFileWindowID derived from nerdtree's s:Opener._firstUsableWindow

I would really like to see what a tight integration between tmux and vim would look like as an alternative to vim-contained systems.