Apart from that good quiz
2. Ancient debris needs diamond pick to mine as well
3. Magma block deals damage as well
4. Slime block and honey block are soft as well
5. Gravity affects anvil and dragon egg as well
6. Clouds are not a block, neither an item
7. Path is shorter than a block as well
(Sorry for my English, I'm from Poland)
There are 6 types of planks.
Spawners are mineable.
Diamond ore is actually from 1 to 16.
Droppers also fling stuff, kind of.
Slabs are shorter than a block.
Air's hint is pretty confusing.
Air should be accepted for "You're able to go through it", as well as lava.