1.Always have someone cheap in garrison. So, they would need to siege your fort for couple of turns.
2.If you leave for AI "road" to your demesne, he would ignore every other province. Let him start siege, beat him.
3.If AI can kill guard, don't set it - free exp for him, loss of money for you. Best way of protection - ring of forts with militamen/slingers insie

Well, in my last game i had problems to afford the necessary forts and the opponent was able to defeat my guards but only barely. After killing the guard he had to hire new units delaying his advance.
hmmm... i'm not sure if it would have been better to just let him capture province after province either till i can afford a fort or he reaching my capital. The bigger Problem was, i couldn't defeat his guards. If i had let him pass he'd have a bridgehead in my teritory.

Uhm... cometent is quiet challenging for me. ;)

When he have bridgehead straight to demesne, he ignore every other province/site.
You can kill AI, farm, wait for him appearing again, beat him again...
You would get level advantage, and eventually you would be able to overcome his guard.
This works only if you can beat him, though :)

hmmm... now that you mentio... er... repeat it.
The AI isn't too clever, is it? ;)

It can surprise you.
If you give him access to labyrinth/ Harpy nest/Knowledge shop/Magic tree, he can hire units there. Minotaur for unprepared army can be pretty rough.

Been playing Eador allot.... learnt many things.

Have a couple more questions?

1) what is the relationship between the map setting for the strenth of independant provinces and the difficulty level?
2) what is the relationship of the general dificulty level and the dificulty level that can be set for a specific AI player?
3) Why some provinces cannot be made happy? (aside from causes from random events) There seems to be a need for at least 2 unhappy provinces, and one time i even thought i saw the unhappy face move to another province when i made its province happy??

Couple of things i have learnt;

1) the inquisition invaders are annoying
2) Enemy armies with phoenixes and gryphons backed up by healing monks are very annoying
3) Enemy Elven archers are VERY annoying
4) While Chasing missing resources you suddenly realize you have just conquered half a 'huge' map and still don't have them - is VERY ANNOYING!

1) Don't really know, so someone will answer this for me.
2) Diff level defines how tough neutral units are(HP), your starting resources, income, population, corruption. How fast will you gain experience and chance of items to drop. AI dfiiculty defines how fast it will conquer neutral provinces
3) There are a lot methods to make people happy. Constructing special buildings in the castle and in troubled provinces. Getting rid of guards that annoy people. If a special event occures in the troubled province don't hesitate
Show booth, Theater for the start. Arena for mid game.

Things 1-3 LOL :)

4) Hidden resources can be made visible if you construct certain buildings in the castle
Herbalists guild - reveals hidden deposits in swamp provinces
Pathfinders guild - reveals hidden resources in forest provinces
Geologists guild - reveals hidden deposits in hilly provinces
After you spot a hidden resource in a province you need to explore the province to find a site that bolongs to the corresponding resource, This will reveal what kind of resource is in the province. In order to make it yours you need to fight units guarding it.

1) Strength of independent provinces - in short, chances to meet 3 or 4 barbarians in neighbourhood. Difficulty doesn't matter.
2) Beginner AI would play with same penalties as Overlord player.
3) Races have different ideology, for example, if you have "Pure" karma, goblins and orcs would be unhappy.

So am i to understand that all this time i have been playing on 'beginner' when for the most part, really I'm not???..... In the sense that i spend most of my efforts striving to crack the tougher provinces, only after which when i find an AI player and their a complete pussy is the 'beginner' level then showing?

So if i put the difficulty level up, i won't notice any difference in the provinces except my units won't gain experience as fast?

am i to understand that If i put the main difficulty up but then put the AI players independant difficulty on beginner, that will only affect how fast the AI will expand but it will not make them weaker verses my armies.... except to whatever extent slower expansion slowed their hero progress??

It is a bit confusing but there are 3 difficulties that need to be taken into consideration.

1) Independents Strength which ranges from Worthless upto Common. This controls the strength of provinces, especially ones outside your starting ring as well as location guards in the provinces. This is always left at the highest setting of Common in my games.

2) Second is your difficulty level ranging from Beginner upto Overlord. This controls the HP level of enemies and how much experience you collect from each battle. Thus on higher levels it takes more to level up your Hero and Creatures and it takes more effort since they have higher HP.

3) Third is the same setting for each opponent. This does the same thing for the enemy by making their neutral fights give more or less exp and monster HP. I believe it's reversed for them though so if you set them on Overlord it gives them the benefits that you would have on Beginner, namely their neutral enemies would only have 55% normal HP and they would level up super fast from getting more exp, 130%, per fight.

Hope this clears up some of the difficulty settings questions you may have. My settings are always Common, Expert and Expert for all.