As a Brit living on this side of the pond, here's my take:

The biggest problem IMO with the US electrical code is the part that the average user is most exposed to: plugs and sockets.

1) The sockets are not protected against insertion of [insert whatever a 2 year old can find around the house here]. UK sockets have protective flaps on the live and neutral, that are released when the earth pin is inserted. This makes it near impossible to stick anything but a proper plug into the live connection. The earth pin on a UK plug is longer than the other 2, and this also has the benefit of ensuring that the earth connection is made before the other 2.

2) UK plugs have shrouded pins. The shrouds are such that if the plug is partially pulled out of the wall then the connections are broken before any of the pin's metal becomes exposed.

These 2 measures are so easy to take for granted in the UK, but when you have a toddler in the US you soon learn to miss them.

Other bug-bears:

1) Those little 3pin -> 2pin adapters that are so easy to get and seem to exist in every house. The ones that allow you to plug an earthed plug into an older unearthed socket. They have a little metal earth tab that is supposed to be connected to a water pipe or similar, but I have never seen anyone doing this. Arrgh.

2) Those flimsy extension cords. They need to die now.

3) The screw-on wire-nuts used in junction boxes. Twist the wires together and then twist on a wire-nut. Although they seem to work quite well if you use the right size for the number and gauge of wires, they still scare me - I'd much rather have a block of screw terminals. Combined with (4) below especially.

4) The mandated use of solid-core wire in circuits. Combined with the 8" length of free wire at the junction box. Trying to get three 12-gauge wires twisted neatly together in a wire-nut is the first excercise in manual dexterity anbd frustration. Then repeat for neutral and earth. And then trying to get all 3 bundles of 3 x 8" wires to sit neatly in the junction box without one of the wire-nuts coming off really takes the piss. It is equally frustrating when something to be connected is multi-stranded. Getting one of those wire-nuts to hold multi-strand and solid-core wires together is a PITA. And working with 10 gauge solid-core wire is a PITA period.

5) The fact that the NEC requires a crazy number of "convenience" circuits in a dining room, but not in the living room. The only thing that gets plugged in in my dining room is the vacuum cleaner. My living room OTOH has a list similar to that in the first post of this thread. Go figure.

Aside from all that, most of the other stuff is ok. The separation of circuits in the panel is far better than that in the UK, which makes working on them easier. No need to plunge the house into complete darkness in order to change a light switch. Just find the appropiate breaker. The nearly-exclusive use of breakers instead of fuses (which are still common in the UK). No fumbling around during a thunder-storm looking for fuse wire. No possibility that a non-technical person can accidentally use incorrectly rated fuse wire etc.


But anyway, just what is scary about Martha Stewart turning an ornamental fountain into a desktop lamp? Waaaaaaaaaargh.


To get back on topic though:
The circuit breaker is matched to the wire used in the circuit. (I'm assuming that this is to code). There will be a safety factor included in this matching so that the circuit breaker will trip before the wire is at risk. You still need to take into account the 15A limit on a socket though (IIRC this applies to the socket as a whole, ie both outlets combined = 15A, not each outlet =15A) You also want to check the amp capacity of any surge protector strips that you use - don't assume that they can handle 15A.
This gives you a maximum of 1800W on a socket, and 2400W on the circuit if you have access to multiple sockets (assuming 20A circuit??). You might want to consider getting an additional circuit added anyway specifically for this bunch of equipment. The existing circuit probably services other outlets too.


Edit:
Looks like Patrick posted whilst I was typing and shares my hatred of wire-nuts.

Further analysis of requirements:
Computer with 550 watt power supply.
Computer with 250 watt power supply

These are maximum PSU ratings, and you are not likely to be hitting them. But lets play safe and take them at 800W combined.

100 watt speaker system
21" monitor
17" monitor

My Dell 21" monitor is rated on the back as drawing 2A, ie about 500W.
Lets assume 300W for the 17"

75 watt bulb
50 wat bulb
Inkjet printer
5 other devices totaling about 100 watts

My inkjet printer is rated at 0.4A, ie about 50W.

So, That's 1975W, lets say 2000W. too much for a single socket.