Hey mate,
Don't know all the answers, but a few I know.
First of all the speeds are just reference limitations issued by the aircraft manufacturer. They come at these numbers after a lot of flight test and performance tests.
According to one of my senior instructors the cross wind limitation speed is defined after they successfully land that plane with a X wind that strong. Its only a speed at which a very competent pilot has landed that aircraft safely above which it would be extremely difficult to accomplish a safe landing but its not impossible.
With the other speeds, they are also given by the manufacturer as a guideline and checked during aircraft type-certification testing. Using them is considered a best practice to maximize aviation safety, aircraft performance or both.
Beyond Vne, the aircraft will go through structural damage and stress beyond its temperament.
Trigger NOTAM
3.7.2 When an AIP amendment or SUP is published, a trigger NOTAM will
be issued on the AIRAC effective date to:
(a) serve as a reminder, through pre-flight information bulletins, of the
coming into effect of operationally significant permanent or
temporary changes to the AIP; and
(b) ensure that users are aware of changes that may affect their flights.
3.7.3 Trigger NOTAM, which remain in force for a period of 14 days,
contain:
(a) a brief description of the contents of the amendment or
supplement;
(b) the effective date; and
(c) the reference number of the amendment or supplement.
Hope this helps.