Oddly enough #1 is the solution to #6

in germany #1 is in use oftenly. it's named "raumspartreppe" translated "space saving stairs". the houses are smaller and if you need stairs to enter the upper livingroom oder sleeping room or childrens rooms you simply use this stairs. they only need half the space instead of normal ones.

#6 - in the US there must be 6’8” / 198 CM of headroom.

#2 oldbuilding redneck repair after earthquake; Zagreb

#27 Well, in the carpenter's defense I gotta say, that doorframe header is nicely parallel to the floor.

#13 Is in northern Germany. It is not a window. It once pictured the towns code of arms. It was made like that on purpose.

#31 Is not bad. Looks more like a solution to a problem. It could be that the sidewalk was created long after whatever pipe(s) is underneath the bespoke manhole cover.