Echo

You can create a map.ini file to override game data. This is a separate file that has to be present in the same folder as the .map file itself. So locate your map, open the folder, and create a new .txt file there (rename it to map.ini) and open it up.

Now you can just paste the armor of the Balrog in this file:

Armor BalrogArmor
  Armor = DEFAULT      1%    ; Likes to have things think they can attack him
  Armor = SIEGE         20% ;25%    ; siege weapons can hurt him
  Armor = STRUCTURAL     25%    ;Structural damage (Ent rocks)
  Armor = MAGIC         100% ; Gandalf can really hurt him.
  Armor = HERO         50%    ; Other heroes can hurt him too.  Watch out for heroes Mr. Balrog!
  Armor = HERO_RANGED     1%    ; Hero bow damage
  Armor = WATER     40% ;100%    ; Arwen damage
End

Change the values to whatever you seem fit. Higher armor value means more vulnerable. Let me know if this works as I've never actually modified armor via map.ini.

You have to edit the map itself. Open up worldbuilder (it's in the BFME install directory) and open the map you want to edit. Go Edit -> Scripts -> New Script.

For this particular case, the script properties can remain the same. For the script condition, just leave it at "True", which means the script will always run because the condition is true by default. Go to "Actions if true". Delete the Null Operation, then click "New". A new window pops up. Go to Player -> Upgrades and Sciences -> Set science availability. You now see some editable text in the text field below. These are drop down fields. Make it so it says:

Player '<All Players>' set Science 'SCIENCE_BalrogAlly' availability to Science availability 'Disabled'.

Then click "OK". If you want to disable more sciences, just copy the action that you just defined and change the science name to the science you want to disable. All of that can happen in the same script. It gets executed once at the start of the game.

It should look like this now:

 worldbuild.PNG   140.07KB   109 downloads

Click "OK". You can save the map now, but remember to make a back up of the original map beforehand, if you think that's necessary.

At first glance I can't spot anything. I assume this started as a copy of the Rohan gate. Did you make any changes to it, except for changing the names?

This is always a good article to check in these cases: https://www.the3rdage.net/item-45

I can only guess, as I've tried the same for my mod and did not succeed. It either has to be added in XML somehow or it's just purely hardcoded in the games' engine. I don't know too much about APT editing either, but if it's possible you'd have to go there and try to understand how XML functions and constructs the interface. I couldn't find documentation/instruction on some of the functions used there.

No problem, trying to help where I can.