To me, the window manager handling the window arrangement feels like The Right Thing, but vim handling the clipboard also feels right (because it interacts with many commands). So I'd like some hybrid of the two options of: 1) running multiple WM-managed vim instances; vs. 2) running one vim with vim-internal window management. I basically agree with the goal of running vim with dwm window management, but it seems wrong to have to reimplement dwm inside of vim, instead of using dwm itself to manage vim windows.
nnoremap <Leader>y "+yy
nnoremap <Leader>d "+dd
noremap <Leader>p "+p
noremap <Leader>P "+P
vnoremap <Leader>y "+y
vnoremap <Leader>d "+d
Also, you can set the default yank register to be your X clipboard. Look into set clipboard = unnamed+ (make sure your vim is complied with X support for both of these)
I've just found out that dwm.vim doesn't work well with tabs just yet though - it copies all buffer windows to the current tab on Ctrl-f (make active window the master focus).
Yes, though you will need a Vim with support for it built. See `:h client-server` for details. (I never really got into using it regularly)