I have played 1.4.2 extensively and then some. I have 900hr of gametime. I have none of your problems. I found ways to play the game to get my desired results. If you don't like how things are going in your 1 campaign, try something new. This is a great game with multiple ways of playing it...
If you don't like Vlan constantly attacking you - do something about it. You probably aren't increasing your garrison, your security rating, etc. Or you could even go attack them. There are many reasons why they are attacking you.
If you don't like what your "master" is constantly doing stuff you don't like, do something about it ingame - leave it/start your own kingdom/join a different kingdom. It also sounds like your not on the newest patch of 1.4.2 or your counting the minor factions as kingdoms being at war (which they don't count, in my mind) - in my games in 1.4.2 the other kingdoms only seem to declare war on 1 "major" faction. As someone that likes creating his own kingdoms, I don't see an issue with hoarding all the fiefs, I do it, so why shouldn't the AI?
Don't know what to do to change/stop stuff from happening? Then think/look-up some videos/ask around.