I assume that in Polyominos shapes must not be places in cells containing numbers. Is this correct, because I think it is not stated in the rules.

Also, I'm a bit confused by the general round note regarding structures that allow for solely diagonal touching of cells: In the example image, would each cell would still be considered to touch two other cells by a side (as in the last sentence of Polyominos). And also in the example: would the right and left cells be considered touching each other (maybe diagonally)?

For puzzle 6 Adjacency Loop I assume, that the loop must not cross itself, as otherwise the example wouldn't have a unique solution. However, it is not stated in the rules, so maybe you could clarify that?

Regarding Doubled Japanese sums: From above I understand that black cells (or parts in the diagram) split the diagram in separate parts with regards to clues and repeating digits. However, I think it should say "each digit appears at most once in each direction" not "exactly once". Or do I miss something due to limited grasp of the language?

(Sorry for posting the questions one by one. I immediately wrote a comment once I stumbled on the question.)

Sorry, but the Polyominos example still needs fixing.

Ah right, the 3 should become a 2. Will get this fixed. Thanks!

Polyominoes: The rules say "different shapes can't touch each other by a side", however, they don't say if SAME shapes can touch each other by a side. I'm assuming the intended rule is that no shapes touch on an edge, regardless of whether they are the same or different shapes.

Simple Kompass: The rules should probably make clear that every cell is part of a region, and every region has exactly one cell that is divided into triangles.

Adjacency Loop: Can the loop cross itself in shaded cells?

As a separate question: Does the solver have to indicate how the loop behaves in shaded cells to get full points?

Simple Kompass:
A little confused by the count of the bottom-left hexagon.
If this is based on Compass, shouldn't the "1" count be 3 or 4?
Which segment of the divided hexagon pie would the last two cells (of the long tail) count for?

Hidato:
Is it sufficient to draw a path instead of filling out every number?