Speaking of Rooster bugs, the Rooster sometimes has a physical collision like a wall or stone or bones, which could be related to the bones issue. Mostly I see this when transitioning between squares on the map or transitioning squares in the caves, but sometimes just entering a cave does it. Additionally after obtaining the Rooster, (but before completing dungeon 7), the rooster is actually there with you inside dungeons as well, just invisible with a pickup ability turned off. The rooster has collision like a rock or bones during the entire time you are in the dungeon which has resulted in a soft lock in Turtle Rock by the lowest rightmost chets below the Rover's room.
Finally, the Rooster will also let you bypass needing to get the mirror shield as it flies over the flame thrower. Or the game is just giving you invincibility when riding the rooster.
The flame thrower should be the only thing that hurts you when riding if comparing the original.