buttons.update = function () {
	...
	var str					= fb.GetOutputDevices();
	var arr					= JSON.parse(str);
	var active				= -1;
	for (var i = 0; i < arr.length; i++) {
		if (arr[i].active)								active			= i;
		if (arr[i].name.indexOf("[exclusive]") > 0)		last_exclusive	= i;
	}
	if (active == -1) {												// OutputDevice has been switched OFF
		active				= 1;
		fb.RunMainMenuCommand('Playback/Device/' + arr[1].name);	// Force second OutputDevice
	}
	switch (true)	{
		case active == 0:
			var img_odev_normal	= utils.LoadImage(imgPath + 'OutputDevice-NULL-normal.png');
			var img_odev_hover	= utils.LoadImage(imgPath + 'OutputDevice-NULL-hover.png');
			break;
		case active == 1:
			var img_odev_normal	= utils.LoadImage(imgPath + 'OutputDevice-Default-normal.png');
			var img_odev_hover	= utils.LoadImage(imgPath + 'OutputDevice-Default-hover.png');
			break;
		case arr[active].name.indexOf("[exclusive]") > 0:
			var img_odev_normal	= utils.LoadImage(imgPath + 'OutputDevice-Exclusive-normal.png');
			var img_odev_hover	= utils.LoadImage(imgPath + 'OutputDevice-Exclusive-hover.png');
			break;
		case active > last_exclusive:
			var img_odev_normal	= utils.LoadImage(imgPath + 'OutputDevice-External-normal.png');
			var img_odev_hover	= utils.LoadImage(imgPath + 'OutputDevice-External-hover.png');
			break;
		default:
			var img_odev_normal	= utils.LoadImage(imgPath + 'OutputDevice-Other-active.png');
			var img_odev_hover	= utils.LoadImage(imgPath + 'OutputDevice-Other-hover.png');
	}
	...
}

function on_output_device_changed() {
	var str					= fb.GetOutputDevices();
	var arr					= JSON.parse(str);
	var active				= -1;
	var last_exclusive		= -1;
	for (var i = 0; i < arr.length; i++) {
		if (arr[i].active)								active			= i;
		if (arr[i].name.indexOf("[exclusive]") > 0)		last_exclusive	= i;
	}
	if (active == -1) {
		active				= 1;
		fb.RunMainMenuCommand('Playback/Device/' + arr[1].name);
	}

	buttons.update();
	window.Repaint();
}

I don't have removable devices to test but maybe you can use this Spider Monkey Panel script.

https://github.com/regorxxx/Device-Priority-SMP

Well you probably can't suppress the preferences popup or close it automatically. You need to take steps to ensure that doesn't happen by switching devices or stopping playback before unplugging.

You can send notifications to other panels by triggering this from a button click or menu item...
And listen in other panels
After checking the received message, used window.Reload()

Try

function on_script_unload() {
   window.NotifyOthers("Test",1);
}

Nope. That one hangs foobar. Probably because all the panels that receive the message will reload and send their own NotifyOthers resulting in deadlock.

Nope. That one hangs foobar. Probably because all the panels that receive the message will reload and send their own NotifyOthers resulting in deadlock.

// ==PREPROCESSOR==
// @name "Playback Buttons - Menu, Stop, Play/Pause, Previous, Next, PBO, RandomizeSelection, QueueSelection, ReplayGain, DSPpreset, OutputDevice - All with rightbutton extras"
// @author "marc2003, modified by Defender"
// @import "%fb2k_component_path%helpers.txt"
// @import "%fb2k_component_path%samples\js\lodash.min.js"
// @import "%fb2k_component_path%samples\js\common.js"
// @import "%fb2k_component_path%samples\js\panel.js"

// @import "%fb2k_profile_path%cui-configs\Defender\JS3\JS3_AudioControls.js"
// ==/PREPROCESSOR==

//////////////////////////////////////

var b_single				= 1;	// 0=Select multiple buttons	Otherwise single button: 1=Menu 2=Stop 3=Play/Pause 4=Previous 5=Next 6=PBO 7=RandomizeSelection 8=QueueSelection 9=ReplayGain 10=DSPpreset 11=OutputDevice

if (b_single==0) {

	// Select multiple buttons 0=OFF 1=ON. Make sure panel has enough width otherwise hover can stay activated with mouseovers

	//									Button	Left click				  Right click

	b_menu					= 1;	//	1		Main Menu				- Help Menu
	b_stop					= 1;	//	2		Stop					- Stop After Current
	b_play					= 1;	//	3		Play/Pause				- Random - PBO will not be changed
	b_prev					= 1;	//	4		Previous				- Seek Back  10 sec
	b_next					= 1;	//	5		Next					- Seek Ahead 10 sec
	b_pbo					= 1;	//	6		PBO			 Dropdown	- Reset to Default
	b_rsel					= 1;	//	7		Randomize   Selection	- Randomize Selection and Play
	b_qsel					= 1;	//	8		Queue		Selection	- UnQueue   Selection
	b_rg					= 1;	//	9		ReplayGain	 Dropdown	- Reset to Track
	b_dsp					= 1;	//	10		DSP Preset	 Dropdown	- Reset to first found DSP preset or Preferences
	b_odev					= 1;	//	11		OutputDevice Dropdown	- Reset to second outputdevice in list (should be standard Primary Sound Driver) or Preferences
}

var transparant				= 1;	// 0=OFF paint background 1=ON do not paint background

/////////////////////////////////////

var publisher				= 0;	// Only one instance of all AudioControl panels can have publisher set to 1

function on_script_unload() {
	if (publisher == 1)			window.NotifyOthers('AC.RELOAD', 'Reload all other AudioControl panels');
}

function on_notify_data(name, info) {
	if (name === 'AC.RELOAD')	window.Reload();
}

Another idea, if you could live with a keyboard shortcut. Put this code in any panel you like (can be a hidden one) and assign a keyboard shortcut to it:

function on_main_menu(index) {
    switch (index) {
    case 1: // triggered when File>JScript Panel 3>1 is run
        window.NotifyOthers('AC.RELOAD',1);
        break;
    }
}

In all your 23 panels you just have to put the on_notify data and with the shortcut you can trigger the reload of all panels.

Open Main Menu together with Shift - under File you will find 10 possible JScript entries you can use for whatever you want. You can address them via script as shown above.

It should also be possible to use fb.RunMainMenuCommand(command) if you want another option apart from shortcuts

And finally, since you don't like hotkeys, you can add an extra menu to panel.js:

After line 105:
this.m.AppendMenuItem(MF_STRING, 130, 'Reload Panels'); 

After line 137:
case idx == 130:
    fb.RunMainMenuCommand("File/JScript Panel 3/1");
    break;

With this, whenever you do a right click on a panel, you get a new command called "Reload Panels", where you can call the script mentioned above in the Main Menu

fb.RunMainMenuCommand("File/JScript Panel 3/1");

edit2: I guess there is a component bug when using window.Reload from a custom right click menu. Because it executes immediately, the script doesn't get the chance to return true from the on_mouse_rbtn_up callback meaning the default menu is not suppressed and appears unexpectedly. I'll fix this in the next release.

function on_mouse_rbtn_up(x, y) {
	if (utils.IsKeyPressed(VK_SHIFT)) {
		window.NotifyOthers('AC.RELOAD', 'Reload all other AudioControl panels');
		window.Reload();
		return true;
	}
	...

Can you point me to where I can find the code for that menu?

This is component code (pure C++) which you cannot override. I'm certainly not adding such a niche case for everyone.