色々書き加えてみました.
neocomplete(neocomplcache), neosnippetなど代表的なプラグインは入れてあるとして,
本記事は数式含みの日本語TeX文章を書く時用の設定をまとめることにします.

便利だったプラグインはim_control.vimとvimtex
参考にしたのはこの辺.

  • https://sites.google.com/site/fudist/Home/vim-nihongo-ban/vim-japanese/ime-control/ctrl-hat
  • http://mmi.hatenablog.com/entry/2015/01/02/003517

vimrc全体は https://github.com/hoshimi/dotfiles/blob/master/.vimrc

.vimrcのTeX関連部分 (lightlineあたりはがっつり削って載せています)

" im_control status display on lightline
let g:lightline = {
     colorscheme: wombat,
     active: {
       left: [ [imcontrol] },
     component: {
       imcontrol: %{has("gui_running")?IMStatus("ime fixed"):""},
     },
     separator: { left : , right :  },
     subseparator: { left : |, right : | }
 }

" im_control
if has(gui_running)
  let IM_CtrlMode = 4
  inoremap <silent> <C-e> <C-^><C-r>=IMState(FixMode)<CR>
else
  set t_Co=256
  let IM_CtrlMode = 0
endif

"" mappings

" move on display lines
noremap j gj
noremap k gk
noremap gj j
noremap gk k

" braces hokan
inoremap {<CR> {}<Left><CR><ESC><S-o>
inoremap [<CR> []<Left><CR><ESC><S-o>
inoremap (<CR> ()<Left><CR><ESC><S-o>

" undo splitting
inoremap <CR> <C-g>u<CR>

" mappings in insert mode
inoremap <C-k> <Up>
inoremap <C-j> <Down>
inoremap <C-h> <Left>
inoremap <C-l> <Right>
inoremap <silent> <C-x> <BS>
inoremap <silent> <C-d> <Del>
inoremap <C-z> <ESC><Undo>

" vimtex
let g:vimtex_latexmk_enabled = 1
let g:vimtex_latexmk_options = -pdfdvi
let g:vimtex_latexmk_continuous = 1
let g:vimtex_latexmk_background = 1
let g:vimtex_view_method = general
let g:vimtex_latexmk_callback = 0

if has(win32)
    let g:vimtex_view_general_viewer = SumatraPDF.exe
    let g:vimtex_view_general_options = -forward-search @tex @line @pdf
    let g:vimtex_view_general_options_latexmk = -reuse-instance
elseif has(unix)
    let g:vimtex_view_general_viewer = open
endif

let g:vimtex_fold_enabled = 1
let g:vimtex_fold_automatic = 1
let g:vimtex_fold_envs = 1
let g:vimtex_toc_split_pos = "topleft"
let g:vimtex_toc_width = 10

" vimtex hokan for neocomplete
if !exists(g:neocomplete#sources#omni#input_patterns)
  let g:neocomplete#sources#omni#input_patterns = {}
endif
let g:neocomplete#sources#omni#input_patterns.tex = "cite{s*[0-9A-Za-z_:]*|
ef{s*[0-9A-Za-z_:]*"

augroup myLaTeXQuickrun
    au!
    if has(gui_running)
        au BufEnter *.tex inoremap <silent> $  <C-g>u$$<ESC>:call IMState("Leave")<CR>i
    endif
augroup END

function! s:TeXDollarFunc()
    " ime fixed?
    let s:cmd = "<Left>"
    if g:IMState == 2
        s:cmd += "<C-^>"
    endif

    return s:cmd

endfunction

個人的には$入力の補完と自動IME切り替え,insert modeでの簡易カーソル移動あたりがかなり良い感じです.
こういうの書くのってQiitaとかのがいいのかしらん…….