Q3.8.3: How do I control how many buffers are listed in the menu Buffers List?

Add the following to your init.el (suit to fit):

(setq buffers-menu-max-size 20)

For no limit, use an argument of ‘nil’.

You can also change this with Customize. Select from the Options menu Advanced (Customize)->Emacs->Environment->Menu->Buffers Menu->Max Size... or type M-x customize RET buffers-menu RET.