(defvar tj-mode-map (make-sparse-keymap)
"Keymap for `tj-mode'.")
;;;###autoload
(define-minor-mode tj-minor-mode
"This minor mode enables my key settings to override conflicting modes."
:init-value t
:lighter " -tj-"
:keymap tj-mode-map)
This last line can be removed if you rename `tj-mode-map` to
`tj-minor-mode-map`.
(add-to-list 'emulation-mode-map-alists `((tj-minor-mode . ,tj-mode-map)))
This is redundant with the keymap setup of `define-minor-mode`, so you'd
be better off just not using the :keymap of `define-minor-mode`.
Can I use multiple :keymap entries, one for each keymap
No, `define-minor-mode` does not support that.
or must I define a minor mode for each of my custom keymaps?
Not a good idea either.