Specifics in ancilliaries and traits.

I'm not entirely new to modding.

But since BI contained a number of new possiblities I have begun to wonder a bit.

I first tried to make Excalibur available to the Roman factions (rather than only the R-B) and opened it up from 410 (fitting date I should think). But then the problem was that a faction heir could get it in say... outside Carthage or Alexandria. Not good. So I tied it to Londinium, but then the character had to be inside the city, which really doesn't fit all that well.
I would prefer if it was availble all over Britannia and only in the open.
Does anyoone know if that is possible? I doubt it, but any answer would be great.

Also, I have considered an even more impossible ancilliary. Something I would like to call Ancestral Sword.
It should only be given when a father that has it dies (obviously it should be possible to get for the original person as well, but it becmes perpetual as long as that lines lives on). But my gutfeeling is that a son that has already come of age can't have any 'contact' with his father, ruining this ancilliary. But if there is a trigger like "WhenFatherDies" or similar please let me know.

Can traits and ancilliaries add to melee, missile or defensive ability (or even shield or armour)? I'm planning on creating some Imperial Swords as well (the Ancestral Swords are for Barbs only), they would be rewarded for good service in the field (and would add loyalty).

Btw, can you tie certain ancilliaries to specific units? I'm thinking of creating a unique ancilliary for the Celts called Cú Chullain (Hound of Chullain = Hound of Culann) who will be tied to Hounds of Culann. Something like a heroic victory where at least three units of Hounds were present in said army.

This is all purely theoretical, I haven't tested any of it and I won't unless I need it for a project.
Here goes:

1:
You can do something like this by using a monitor_condition CharacterTypeNearTile and choosing the parameters so that it triggers in most part of Britannia (I think this uses a square, just try around a bit)

2:
The main problem here is that we can't stop an ancillary from being moved.
I could think of a way to do it if the ancillary coulnd't be given to another general, but currently, I don't htink it's possible.

3:
Dunno, but I guess you can only change hitpoints.

4:
This is difficult...
If you are positive that the Hounds are the only unit in the player's army with the berserk ability you can probably use: I_BattlePlayerArmyPercentageOfSpecialAbility
Obviously this wouldn't work well with other units ;)