Hi Kezbed,
I too have the 1,6 FSI Sport, a 52 registered one. I wouldn't worry about the rattles when starting the engine up, they all do it, the fuel is fed to the engine via a common rail pump which works under high pressure and the noise happens when the pump is being pressurised. The engine soon settles down and runs smoothly.
Things to watch out for are uneven tyre wear (anti roll bars often go as can tracking), wheels being buckled, look out for pot holes! Especially look out for the engine management light comming on - it could mean new coil packs (advanced spark plugs is a good description) but Audi have extended the warranty for these to 5 years so peace of mind there plus there are improved parts probably on your younger A2.
My car has experienced all of the above in a similar mileage. But it is a great little car to drive and touch wood I have had no problems recently. I think all cars have their glitches and the A2 is no different, but few are as much fun for the money.