If you use other packages that change keymaps, remember
that these packages will assume native Emacs. So let the other packages
alter the keymaps, and then change to VIP mode, usually by calling
(vip-mode) from the hooks for those packages.
VIP is designed as a minor mode -- a feature you can turn on or off. Therefore, mode keymap changes must be made to the underlying major modes, not VIP itself.
This question usually arises in the context of C-c bindings.
In Emacs, C-c is reserved for users and packages as a general key.
Normally, VIP binds C-c in Insert and Vi mode to keyboard-quit,
to be compatible with VI. vip-make-emacs-keys-visible will
bind C-c to vip-ctl-c, making C-c act like a Emacs key.
(you might want to change the bindings in the vip-insert-mode-map and
vip-mode-map yourself, if you want other VI bindings to remain)
Any C-c binding from the current buffer major mode will be
accessible now under either Vi or Insert mode.