Sort criticism by whether it describes a problem or prescribes a solution. Problems are almost always worth hearing even when the suggested fix is wrong. Look for the note that repeats across different people — that is the real issue. Ignore criticism of the thing you deliberately chose to do, and never revise while you are still stung.
Useful criticism describes an experience of the work — where attention dropped, what was unclear, what felt unsupported. Bad-faith criticism describes you, or asserts a verdict without an observation behind it. The first is information regardless of tone; the second is not.
No. Acknowledge substantive points and let the rest sit. A long public defence signals to onlookers that the criticism mattered more than it did, and it rarely persuades the person who made it.
That is data about reach and framing rather than about quality. Check whether the title told people what it was, and whether you published where the relevant audience actually gathers. Good work with no distribution looks identical to bad work from the outside.