1. The keyboard is probably different to the UK version e.g. it won't have £ sign on it. You will be able to change the region in Regional Options in Control Panel but have to compare it to a UK one to find out where all the symbols etc. are.
2. click here may be able to supply a battery. A google search will bring up other suppliers.
3. Again try the one at 2. or google for others. Sony have their own site at click here
4. Not sure what version of USB it has. I would think most would work but you might have to fit a PCMCIA/Cardbus USB 2.0 card to exploit the full potential try click here for this.