something that that you thinks would help out when building large structure.
I have two suggestions that i think would help out, in my experience when building.
have the ability to cut inwardly like the terrain slice vision and be able to stop on every block, this would also be helpful in design mode.
to speed upp large or detailed buildings a copy and paste tool would be most helpful. my suggestion is that works by you placing two copy blocks and then hits copy on the building menu. then you hits paste and then put it down like a furniture. but have the ability to change mode between overwrite or not overwrite.
I hope you enjoy my suggestions.