Not sure why your abilities would cause a lock up.
Check to ensure you don't have any mapped keys that do an action which calls an earlier mapped key, like this:
Hotkey Causes A > Which does B > Which calls A > Which wants to cycle into B....



If you ran the wizard, you'll have FTL modifiers set up.
Which means you can ditch Focus entirely for assist purposes.

When you push "1", it will send "1" to every DK.
But the other windows will auto assist the first window before pushing "1".
So the other windows auto assist the current window, without need for any assist mechanic in your macros.

You can still do something like:
/cast [@focus] Strangulate
Which then allows you to set a Focus for a Crowd Control or PvP effect, instead of using it for assist purposes.



You can have IWT on its own key, I do too.
However, you can build IWT into your mapped keys to automatically be pressed most of the time.

I did this with a few steps.

Create an Action Target Group, called Melee which the DK's belong to but the Healer does not.

Create a mapped key.
Does not need a hotkey.
This sends your IWT Keybind to the Current Window.

In any DPS key that you spam, insert the following action:
Do Mapped Key (The Above no-hotkey IWT) with a Target of Group (all of): Melee (the ATG with the DK's only).

So your current spam '1' key used to look like this:

Hotkey: 1
Step 1:
- Do Mapped Key Action, FTL Assist Me, Target: Current Window
- Send Keystroke Action "1", to Target: Window All With Current

We modify it to be:
Hotkey: 1
Step 1:
- Do Mapped Key Action, FTL Assist Me, Target: Current Window
- Do Mapped Key Action, Unnamed Mapped Key that sends IWT, to Target: Group (all of) Melee ATG With DK's in it.
- Send Keystroke Action "1", to Target: Window All With Current

Lastly make another mapped key, this is a Toggle Key.
Give it a hotkey of some sort.
Two steps for this one.
Step 1:
- Keymap Actions > New Mapped Key State Action > Unnamed Mapped Key that sends IWT.... set to "On".
- Pop Up Text Action > "Melee IWT Mode On"
Step 2:
- Keymap Actions > New Mapped Key State Action > Unnamed Mapped Key that sends IWT.... set to "Off"
- Pop Up Text Action > "Melee IWT Mode Off"

In practice...
You spam your Spam Key... I think "2" from the information you listed in the previous post.
Your toons assist the active window.
Your toons Interact with Target, automatically because you pressed "2".
Your toons do the macro that is on "2".

When you don't want the "auto" IWT.
You press your Toggle key twice.
When you want it back on, press the Toggle key again.