If a clan declares war on you, does it appear anywhere else other than the "Events" section? How long does the war last? A clan declared war on mine and I see a peace treaty we have with another clan but nothing on the declaration of war so it's confusing - i.e. I don't know if we're actually at war or not...

In the events, the message about the declaration contains the exact time when the war will begin between the 2 clans.
The war ends if you capitulate.

"If you surrender, a temporary peace treaty will be made between your two clans (you cannot attack each other for a week even after canceling the treaty), and the charge level of your soul-well will be decreased (it can go to negative), and the winner's soul-well level will be increased by the same amount (it can go above maximum). The level of decrease depends on the size of the soul-well and the power relation between the two clans.

Capitulation is automatic, if you have at least 50 duels in a war and after a battle one of the following conditions occurs: - war is in progress for at least 3 days and one party has won at least twice as many as the other - war is in progress for at least 1 week and one party has at least 100 more victories than the other - war is in progress for at least 2 weeks and one party has at least 10 more victories than the other If a war goes on for 3 weeks it is ended with a draw; no one gets SE and no peace treaty is made."

/from http://web.me.com/loquacious_4ever/Tina/FAQs.html/...

Thanks, that is what I missed - the start time (confused it for when the war was declared because of the time difference).

I have a question regarding clans wars. When two clans are at war, does it mean that all members of one clan can attack all members of other clan? Example : Can a lvl 9 character from clan A, fight a lvl 3 character from clan B, when clans A and B are at war?

No. It decreases only the time you have to wait until the next attack against the same opponent (to one hour), the rules of the duels doesn't change.

If I have my duels set to 30 per day and I go to war with someone who has a character one level below me, can I attack him? I know normal duels only allow you attack someone your level or higher, I was just wondering if that still is in effect for wars.

How is the reward calculated when your clan wins a war?

I don't know. What I know is that wars are very poorly designed. Whatever you will gain as the prize will be much less than what you will lose with the CoD. Unless you declare war on a dead clan ofc.

Cruel.