Sorry, crooked isn't the best word, but I can't think of a better one.
I'm still quite new to OSM, and I want to start adding the buildings in my town. When I open the edit option though, the map overlay is at an angle. It's not a massive amount, but it's enough that you can see one sometimes two sides of most buildings, so the roof isn't aligned straight down, if that makes sense?
I live near Aberdare in South Wales, and you can see that where someone has added some buildings in the town centre at some point, they're now not aligned with the map overlay:
Do I draw around the roof that I can see on the map? Do I edit the existing buildings so that they line up with the overlay? I'm not sure what the best course of action is for something like this.
If you plan to add many buildings, I suggest using josm instead of id. It's a much smoother experience.
Usually, you take care of the "imagery offset" in the beginning of a mapping session. For this you use gpx tracks to align the different map layers. You can also use other shapes you already aligned properly in the past. With newer or different imagery it can happen that the imagery is slightly off.
For a building, you usually use the roof and move the final shape to a corner which is visible on the map. You may have to adjust things if the roof has a different shape than the building.
Yes, you move all buildings if all of them are off. This is easier done in josm than in id. You can also align the map to all the other buildings and hope that some day someone else will align it. Hint: this will be you, but in the future.