I plan on doing a stage 1 apr tune anyway, and it's a dsg and still under a lot of warranty.
In general I totally agree with you and this car in particular looks like it may have been driven hard. If it was local I would feel much better but it's several hundred miles away.
You're probably right though.
Don't count on the warranty for engine and trans repairs if you're tuned. Google VW TD1 Flag. Long story short, if your engine and trans fails and you're tuned, VW Corporate will likely deny any warranty repairs. If it's a third party warranty, it's a coin toss.
That being said, I tuned my GLI APR stage 1 ecu/dsg tune at 1100 miles knowing that. But every mile is driven by ME. I don't beat up my car, so the risk is a lot less.
Just think smart. Unless you're paying in full, you'll be paying the car off for 5 years most likely. If you blow the engine due to the former owner being an entitled 18 year old showing off to his tinder date, add $5-10,000 to your budget.
Paranoid? Yes, but I like sleeping well at night.