@Joseph W. Doherty  Thank you so much for this explanations. It really helped. And the last question, I didn't get regarding this point: "#3 Not quite correct..." I think I told the same as you, let me rephrase myself.

During congestion: Traffic in LLQ can't exceed bandwidth which was configured in

priority

command. Because there is traffic policers which triggers if traffic in LLQ and wants to exceed bandwidth configured in

priority

command.
If there is no congestion: Traffic which supposed to be in LLQ (But not queued. Because if there no congestion, then there are no queues) can get all bandwidth which is available at the moment.
Additionally: If there is traffic only in hardware queue, then there are no any LLQ and CBWFQ queues. Only FIFO. This is considered to be not a congestion. If traffic overflows the hardware queue, it's going to software queue and this is considered to be congestion. In that case LLQ and CBWFQ queues comes into play.

Is that correct?