Disable num lock indicator LED or reverse keypad so when num lock is on, indicator light is off

In X11 (on console I don't know) you can do it by redefining the behaviour of the Escape key. I looked at the "shift(break_caps)" definition to see how it works, and adapted it.

Look at this answer on xkb for more details on how/where to put the locally modified files and load them.

And for doing what you want, you need in the local symbols file (eg: ~/.xkb/symbols/mysymbols) a section like this:

partial modifier_keys
xkb_symbols "esc_breaks_caps" {
    key <ESC> {
        type = "ALPHABETIC",
        actions [Group1] = [
            SetMods(modifiers=none),
            SetMods(modifiers=Lock,clearLocks)
        ]
    };
};

and in the local keymap file (eg: ~/.xkb/keymap/mykbd; you can create it with setxkbmap -print > ~/.xkb/keymap/mykbd ) change the xkb_symbols line to add +mysymbols(esc_breaks_caps).

You can now load it with: xkbcomp -I$HOME/.xkb ~/.xkb/keymap/mykbd $DISPLAY and pressing Esc will remove the CapsLock state (actually, the effect happens on the release of Esc; I think that only modifiers keys have immediate effect; others the effect is after their release.)

Oh, if you want to also swap Escape and CapsLock keys; then use this instead (and you put "+mysymbols(esc_swap_and_breaks_caps)" in your mykbd file):

partial modifier_keys
xkb_symbols "esc_swap_and_breaks_caps" {
    replace key <CAPS> {
        type = "ALPHABETIC",
        symbols = [ Escape, Escape ],
        actions [Group1] = [
            SetMods(modifiers=none),
            SetMods(modifiers=Lock,clearLocks)
        ]
    };
    replace key <ESC> { [ CapsLock, CapsLock ] };
};

note the physical keys are <CAPS> and <ESC>; <CAPS> (key engraved CapsLock in your keyboard) send Escape and <ESC> (key engraved Esc) sends CapsLock, whith <CAPS> (sending Escape) also unsetting capslock state

in Linux Mint, this is easy:
1. open up 'keyboard' in settings
2. click on the 'Layouts' tab
3. click on 'Options...'
4. Under 'Miscellaneous compatibility options' there are many helpful options, including:

• Default numeric keypad keys
• Numeric keypad keys always enter digits (as in Mac OS)