Home in FL was wired with 3 wire plus bare copper ground romex in every box around 2000.  Is that normal for romex wiring today?
 
I have added post build electrical and it was easy with plastic boxes and romex but I prefer adding conduit in the midwest to adding romex box to box.
 
There are also firebreaks in every wall which dinged my post wiring a bit for adding automation stuff on new walls (touchscreen stuff).  (this must have been some new FEMA building codes?)
 
One of the things that I have done in the midwest post contruction is add more breakers and circuits.  I divided up the 2nd floor bedrooms and added circuits to the master bathroom / bedroom, garage, media room, kitchen, basement,et al  (master bath has much electrical).
 
IE: server room / area in basement has 4 circuits today which are separate from everything else in the basement.
 
I did the same with the media room dividing up the lights, media circuits and just outlets to autonomous breakers.
 
Maybe I overdid it a bit as it does provide me with a great deal of granularity when I look at my fuse panel.