People complain about non target aoes opening a war in the current system. You say that's a game problem, not a clan war problem. OK, fine. Call it whatever you want, but they are related, and can be discussed as such.
To your direct question: if I declare on a clan, and they kill my clan members 5 times, they should open war. I am fine the the declared status and 5 kills.
The detag issue is my only complaint in this thread. I think the war declaration system is fine. I think the 5 kills to open a war is fine. I dislike people flagging with non target aoe's, but I'm sort of whatever on that.
The stuff about dragons, etc. All dragons should be pvp zones like at swords and siege.