Need Opinions. Have nothing to compare to.

I think A/J covered most of what I would have said.

Manifold vacuum strongly relates to load: Its a result of the combination of throttle opening and engine speed and efficiency in drawing air. I suppose it will be best when you see it for yourself. (However if you are familiar with modern cars with closed loop EFI, the MAP is the same thing, just viewed in terms of absolulte pressure.)

Lazy is a term sometimes used to describe throttle response. I believe what he probably meant.

Distributor curve. I agree it is best to know when it stops advancing. Also two points is not enough to know the shape. It may be a two stage advance. It didn't ping at WOT, so it was never too advanced at full load. The advance may slightly retard at higher rpm. Depends on the ignition box and distributor. Since your not turning it much past 5000 rpm at this point, I don't think its that important.
It's likely the difference in timing between the two lights is the electronics. At higher rpm, the slower one will show up. Or if you ignition is multi-spark, who knows. Doesn't matter as long as its consistant.

On the Dyno. Usually shops will only hit the record at full throttle. They do this because recording while the bringing the engine to full power is confusing - as you can see.

I honestly think the lean mountain we are seeing is the throttle being squeezed on. AFR should go leaner with more throttle (load) until 70-90% full throttle, then it needs to go richer. ( On Holley type carb, that additional fuel is supplied through by "power valve" opening.)
See if the guys will let you do the driving next time you go.

With Dynojets, the rpm comes from the inductive pickup. The software then matches it up with sensor info from the drum. IIRC torque is derived, based on its assumption of gear ratio (including tires). If you get the files, it will show speed in mph (from the drum), and the missing data may then appear.