Kerbed alloys I think are a good indication of how well a car has been treated.
Hmmmm. My alloys are kerbed, but I would vhermently dispute that my car as a whole has been mistreated!

Moisture in the third brake light in the rear spoiler, this is very very common and you should have it fixed before picking it up, I have had mine done and it was fine.
But the crucial thing with this issue - is to actually check the alignment of the rear washer. Most are factory set at the '12 o'clock' position, ie, straight up directly at the brake light, but the official technical literature states they should be aimed at the '2 o'clock' position, away from the light.
I would avoid a DSG as a second hand purchase in case anything goes wrong or make sure you have a good warranty in place, think it needs an oil change at around 40k.
Sorry, but the DSG is a superb bit of kit, and is just as reliable as any other gearbox - manual or auto. Like any component on a car, if the DSG has been abused, ie regular launch control, or regular drag strip useage - then be prepared for an early DSG bath.
And the DSG
must have an oil
and filter change every 4 years or 40k miles, whichever comes soonest. If the car is driven hard, or has had a remap, it is wise advice to half, or even quater in extreme useage, this interval.