From someone who had wars near enough every night. That's far from fun. Can't help but feel you believe this idea will benefit your guild, which is why your pressing for it. Imo only changes that should be made to castles is the cost to war them should be increased to 10m, the income produced should be halfed. The stone salvage npc should be in a sz.
Making the castles so rewarding only causes a monopoly for the guild who holds them. Allowing for easy buffs.
Changes to the castle systen have to be right for the server and I feel the current monopoly of rewards is the wrong way to achieve this. We create in balance. Half the people who go to wars would fight for them without the rewards as the always have.
Power switches and changes, 1 player could quit or change sides, causing a power shift. Always been the same.