System info is stored on the PS3's flash memory.

I hope that answers your question, and everyone else's.

Not every.
Many yes. Some has optional install. A few doesn't at all.

That's the way it is.

Since day 1 the PS3 was launched has.

Actually, back during the days in the early firmware stages, the PS3 gets amazingly hot when watching Blu-Ray movies.
There was a firmware feature to increase fanspeed accordingly during then, and it is a widely known technical fault that needed to be fixed.

Turns out Sony couldn't find a way to implement increasing the fanspeed through firmware. It's either asking the fan to go full speed which could get bloody annoying when watching movies or keep it down all the time. Also another reason why 60GB and 20GB had so many overheating messages, many of which are also false.

When the 80GB (with PS2 emu bc) and 40GB (1st gen) came around, Sony did change the fan using PWM connection.
The PS3 could tell the fan to adjust the fanspeed then.

Yes.
Any region can be played, PS3 games only take note.

Most if not all PS3 games have Dolby Digital 5.1 support for 5.1 setups.
There are quite a number of games which has support for Linear PCM 5.1 as well.

The DDW3000 is pretty much fine as it is though IMO.

You can.
But ONLY with this: http://sourceforge.net/projects/libusb-win32/files/

I've been using my DS3/SIXAXIS on the PC for nearly 2 years.

You should have taken out the Blu-Ray disc and force shutdown your PS3 instead of let it hang like that. It has happened to many and it isn't really that uncommon anymore, shouldn't do any harm to your PS3 really.

Sometimes the PS3 does lock-up when things really get too toasty and the fan fails to kick into high-speed mode.

Just buy US PSN card and forget about MY PSN.
It is hopeless.

Looks like something got shorted.
The HDMI controller is connected to the audio chip in the PS3, either one could be at fault.

I think you should just take it to Sony with a receipt and the entire box to show that it is still under warranty, even if you did not registered.
Not sure if they would look at it or not, but I think they should with a little bit negotiating.

Sort out by names is impossible.
Only way is to differentiate by using different icons.

The PS3's XMB has a very poor grouping capabilities. Sony should definitely improve this on the firmware.
Why can't we sort everything out in our way, I don't know. It isn't that hard to implement anyway.

Yes, the user accounts your PS3 logs in with. Not your PSN friends list.

No one dare to come up with a list yet.
You're dealing with MONEY here.