One last Q on the 747, what is the maximum dive rate that the wing and nacelles can handle structurally before -?

Since nobody has ever flown one that fast deliberately and probably never will, it is impossible to say and in fact it will be expressed as a Mach number, a value which changes with temperature, so a "mile per hour" figure is not a lot of use to you.

However, B747s have accidentally exceeded Mach1 without major damage.

You do not climb a B747 close to stall, it would not climb efficiently, we normally climb at 250 knots below 10,000 feet and around 325 knots above that level.

We are interested in the most efficient climb, not necessarily the fastest climb.