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 ;)