No, Japanese are only disgusting. Ole Lovecraft was disturbing. And creatures which are serious about defending themselves usually grow huge claws, fangs and run really, really fast. Spitting acid/poison helps, too. But not vomiting shit and carrying one's offspring in one's own eyesockets.
They look horrifying but their closer to living animals now than yukkuris.
Yes, the two ground ones look remarkably similar to certain very small bugs (I can't recall their exact names because I'm bad at biology, but most small animals have those features).
The flying one looks like a weird jellyfish. There are advantages in keeping your babies inside you, though (like how the frog stores fertilized eggs in their stomach) so why not have them able to move?
Look at Reimu's poo-poo easy!Reimu will sing a song!
Yunyunyu~~Easy!itTake