Yes, mirror mode 1000ms is the delay in which the bot *notices* changes, so if a rock's gone, it will take the client a whole 1000ms to detect that it's gone, I always tell users to lower it for competitive scripts like mining (competing for ore)
As for mirror, I personally feel safer with mirror mode, but I can't prove why, and I've still been banned with mirror client so it's not a magic bullet.
You forgot to mention if you only botted on a single account, or multiple at the same time?
In any case, interesting read, good luck on future botting ^^ :D