As I said in another post, I do think that the difference between numbers of family members does have too much of an influence on things at the moment - there are not alternative tactics, if you have fewer family members, you'll lose. If somehow this could be balanced (possibly increasing the food requirements and yields from certain activities) so that having fewer actions per turn doesn't matter so much as you don't have to gather as much food, that would make it more viable.
Taking plots - perhaps only be able to take plots adjacent to the unbroken 'main' section of your own lands. As we've seen in one of the alpha games, at the moment you can end up with random scattered individual plots when both sides are trying to take everything, which could result in losing your house with nothing you can do about it (though some of the ideas mentioned in your post would cover that).
Being able to destroy things yourself would also be good - disassembling huts/fences on common land for example. Quicker way to gather resources, and a tactic to help destroy other families.
Very small chance of death when gathering in forest after x number of days?
