Decorated pots do not have collision on top

i actually like this because it adds a cool collum like design when stacked upon eachother

All blocks only occupy 1 space; there's no single block that prevents another block space from being occupied. (Beds and doors are 2 blocks.)

Not a bug.

Probably intended because lecterns work this way too.

And fences, and walls (higher collision), and banners, and anything with a model bigger than 16x16x16.

There's honestly no question about it...