For 2nd one, it depends entirely on the severity of the earthquake.
For the 3rd one, that really depends on what the shape of the rock is, and what its radius.
Assuming it was a cylinder shaped rock (a pillar, basically) and had a radius of 1 meter, then:
Simply breaking or fragmenting it will grant 0.012 tons of tnt, or 9-A (Small building level)
Violently fragmenting it will grant 0.1 tons of tnt, still 9-A, but about 8.3 times stronger than simply fragmenting it.
For the 4th one, assuming it was an average thunderbolt, then google, our friend, tells us it yields as much as 1 million joules, or almost 8-C (Building level)
Granted, I recall hearing people not wanting to use lightning and other stuff to scale attack potency or durability, so...
And for the 5th one, I'm not 100% sure, but I do recall something like that being high into the 4-B tier.