I like the idea of Estoc's Edge. That having been said, I think the bonus should be permanent for so long as Clan membership does not change. This would motivate a Clan to field a group willing to fight until five Weekly War Events are won and they have accumulated the maximum bonus, and stick together long after that. Also, losing a War would not set such a team back then and the incentive is there to build right back up together for the next week's war, instead of having Members leave for a "better" Clan. This would more quickly build Tournament-ready Clans in my opinion too.
Quest locking sounds good too, but as others have already said, it's rather pointless without also closing off hitting outside Kingdoms. Couple that with not being able to Attack or be Attacked until you reach 50% Troop strength and I cannot help but think that we will still all just be fighting from a new pin. Terribly boring. The only way I see this working is to prevent outside interference altogether (but allow Ally trading for obvious reasons) and have both Clans' Members all enter the War Active as done previously with Tournament play. This mechanic would favour the more-Active, more-aggressive Clan and make for a much more exciting and strategic contest.
Remember Devs, when we want our friends to pile on the bad guy here we have an OSW. A System War should be treated as a Cage Match, may the best Clan win. Many, many more Clans will participate week after week if the thought of being shelled by outside hits is off the table.
On that note something should be done to award losing sides. These guys and gals lost tons of gold and walk away with squat. I definitely think they should get to keep the Estoc's Edge at the current level should they stick together, but on top of that how about a few concilation Crystals to help rebuild, maybe a Mithril or two? I realize there's no point to it but a nice thanks-for-playing gesture goes a long way.
Cheers!