If you have placed an item (F2 data structure), then use the "drive" function to test it and afterwards return to editor via "esc", you will return with the previously placed object (e.g. a normal street block).
If you did terraforming (F1), then you will return with the lowest level of the selected terraforming (e.g. small hills (F1, field 2), but in the F2 data structure (in this case you will have selected the normal streets! Furthermore, you will have in the selector the latest block you have placed in F2 (e.g. a scenery house).
To top all of this, if you place objects (F4 data structure), then use the "drive" function to test it and afterwards return to editor via "esc", then you will return with the previous selected F2 object to be placed and an level one F2 data structure tree. But the icon selected in this one will then selected totally independent of which item you had selected in the F4 data structure.
=> Why do we jump back from F4 to F2, if we maybe need to replace F4 objects instead of F2? Just assume you zoomed in really close towards a precise object placement and then come back from the test drive and you are suddenly inside of a big scenery house to be placed.
Deleting objects:
For example, I place the small white objects with the arrows on the sides (F4-1-3) of it. I realise I) want to change it. So I select the delete button and then select the object to be deleted. After I did this, I want to place it again in a more refined position. Even though the data structure is still open and the object is selected, I need to double click the object until I have it back in focus. Why do I need to double click the object? If this would be in F2, then the whole block data tree would minimise and I would need to reselect it again. Why are there this two different behaviours? Just to be precise, this problem with object deletion and double click doesn't occur when you use the shortcut by pressing X.
Selection tools:
If you have a map that contains embedded objects and use the "select all" function to move the complete map, these objects get selected but not copied.
If you select the button (+) for adding an element to the selection, why do I need to press (-) to deselect it again? Why not simply click once more on a selected area to deselect it again?
Feel free to add on this list, this one were just some things that annoyed me while building
