None of these are necessary. Actually, I wouldn't want any of them to come into effect along with houses. The first one voids the ability to get rid of spies and people who are wasting efficiency in a fief. The second is incredibly vague, but if I understand it right, it would destroy the economy by adding a massive progression nerf in addition to chadz's multiple speed and gold nerfs. The third would make taking over fiefs childsplay. The fourth removes the ability to scare off people from coming into a fief and ruining efficiency. The fifth is another progression nerf to make a slow Strat even slower.
The houses themselves though are a good idea. It would make sense that house owners don't have to pay a visiting fee and add to the population. However, I think there should be a means for fief owners to either evict house owners, take a percentage of their profits/production, or just make things unbearable for them.
There is no crafting efficiency loss due to lots of people being in a fief anymore so your arguments against 1) and 4) are not valid. Also there's no need to scare off people making houses, as the more you have the higher your fief tickets, the better your potential recruiting and the more you can make in tax. If you really want to do it then raise taxes to the max and take half the gold they make. That will soon move people out.
Not sure what you mean by a massive progression nerf for 2). Crafting is still there but is house based so that instead of there being clan crafters that give to their clan and get nothing in return, there are individual crafters that sell to everybody. If you want to stop someone buying the goods/equipment, then wait until they have bought it and then stomp them in a battle or raid.
3) I see what you mean with 3 - so agree that can be left out with the current recruiting efficiency system being kept but I would leave in the conscription option for fief owners as if they do it their crafters will suffer and may leave. I'll alter the OP
5) Is just something that fits with the overall theme. Craft goods in a village, sell them in a Town. Not sure how it slows anything down, you can still travel across the entire map to sell in the furthest possible town from where you bought the goods. However it also puts more importance on Towns as you can make a lot of money by owning one and taxing the goods sales there