I don't work for XJT, but a lot of times you'll make these harder than they need to be. Just think about what you'd do if it was your a$$ on the line. Some of the ones you listed are regulated.

Approaching a Class B airport ATC clears you to descend below the floor of Class B
Refer to FARs

Cleared for an approach 80 miles out at FL240
Refer to FAR/AIM

Weather goes below approach mins outside the FAF....inside the FAF?
Refer to FARs

If you notice there is a T-Storm right on an airway, do you always ask ATC for a vector or is there another procedure?
Use common sense. I'm not flying through it. Usually I ask ATC for a turn to the left or right unless it is imminent for some reason (they denied my request or something) in which case I tell them where I'm turning to avoid the weather.