1. When I register for a fortress siege, when does it start? It once started 1 hour after I registered, the other time it took 5 hours. How can I check?

2. When can you siege a fortress after the last siege has ended (what's the cooldown)?

3. When and how can I siege my own fortress - I mean the siege where the guards don't attack you and you just farm KE?

1. Must start 1 hour after registration. Otherwise its bugged.
2. Not sure about cooldown, but I think is 1 hour after siege ends, you can register again.
3. You must be in the same clan who own the fortress and guards wont attack you.

About sieging my own fortress - how do I do that? Because the suspicious merchant doesn't let me register for a siege, he tells me I already own the fortress. So, there's another way to do it ?

I forgot to mention that if you want to make siege for your own fortress, you must register with another clan lvl 5+
And then kill guards with clan who own the fortress.