Suggestion about alliences pvp war
I like very much the DoF idea of a pvp war among cities and I'm very excited to see how this will be developer with the guilds/alliance system.
BTW I think that with the alliance system, would be good to divide the land in a "pvp" zone with conquerable cities/resources and a more "pve" zone that can work as it is now, i.e. npc towns siege, pvp player vs player ecc.
IMO "pvp" lands can provide to players/guilds more resources than the "pve" one, because guilds can lost their conquered castles/lands.
An other idea can be to make npc sieged towns, in the "pve" land, enemy for a period, with no possibility to commerce/enter in, while an ally npc town can support your army when you are sieged. So you can ask support to npcs paying crowns and the attacker can ask help to a friend to deal with the npc supporting army.
In the "pvp" land all this will happen among players/guilds/ally, so it is done by players.