Door structure is strengthened, when ever you cut an hole in a fuselage such as windows it is a weak point the surrounding structure is beefed up, as with floor not really as said, depends on what it is used for, but as said the floor has to be crash tolerant, as indeed does the whole aircraft. Even when you see an emergency cut here panel, the structure is no different, it just means items like electrics, fuel etc has been routed around it to leave the structure clear behind it.. last thing you want is cutting through live electrics or fuel lines…….

If you see some of the older high houred 737, 747’s etc and look at the windows, because of pressurisation cycles weakening structure around windows that can lead to cracking they have a metal scab patch “belt” riveted along and over the window cut outs to beef the area up