Warclaims should not be deniable. By definition they are claims of war. They should simply be the polite (but required) written declaration of war and that is all. Denying a warclaim oocly is the biggest barrier to role play ever.
People are already raiding/warclaiming others? Get a grip. It hasn't even been 2 days since the map is out. Enjoy the map by exploring it. Not getting your swords out.
I think war provides RP for some and drama for others. If you're a leader, and you're trying diplomacy or what not, you get some really fun RP. If you're a grunt, you're really only PVPing, and accusing people of hacking, and bitching. But I agree, you shouldn't be able to deny warclaims