but this time I just mean stuck on talk about the roof. I understand that the rules imply some answers to this but they are not clearly stated so I just want to see how you nice people weigh in. Attacking to/from roof. Cerb says to draw line of sight in 2D for attacking different levels but then ignores a wall (in 2D) in that line of sight in all of the examples it's always an adjacent wall of the occupied building and this makes the most sense, is this how you play it?

Inside building/ on the roof- can units attach each other? The rules say no but that is following the same logic that prevents unit from entering a building from the roof. It's clearly stated that "on the roof" is "outside the structure". This I could see going either way an argument on one side is that the top floor of the building has an exit to the roof everywhere in which case units inside the building would get hard cover and rofftop would get soft.

Can you jump off the roof? If yes do you count vertical movement down?

The rules are a complete mess concerning roofs, I don't know why they just disn't say that models counts as in the structure if on the roof, solves so many problems. In the meantime I have an easy solution I use - We don't go on roofs or just play it how you feel is right.