There are a few more settings that I want to implement but not until after beta. Tribe alliances is a big one, so you can share the stronghold outside of your immediate tribe. I also want to add day and night settings for the guard, so cities can be locked at night if you wish.
I've been thinking about the great stories in human history involving breaching the gates: the Trojan Horse, the Gates of Toledo, and many more. A common denominator is that an enemy agent can open the gates from within. But I can't just let anyone open every gate; that would be chaos.
My solution is that the tribe can hire a gate guard. The guard is useful for two reasons: 1) it would allow a tribe member to open the gate from outside of it without another member being online, and 2) it would provide the interface for determining who has opened the gate (by asking the guard).
So now, an enemy agent could open the gate, but only by first defeating the guard. And the guard, in turn, could report to the tribe who the perpetrator was. In other words, room for intrigue and roleplaying...
I also plan to have detailed controls on who the guard will let in: tribe only, kin only, and even by race. I had not planned to have racial cities, but if players really wanted to create a Mouse-only city, I am certainly not going to stop them.