Cambelt and water pump changed?
Definitely worth getting haladex and gearbox oil changed for peace of mind.
Do all electrical items work? AC, headlights etc.
As it's quattro are the tyres the sane brands and even tread on the same axles as uneven tyre wear can damage the quattro system.
Also worth checking YouTube for buyers guides.
Remaps - have a look at Celtic tuning website as they have a configurator which can give you an estimate on upgrade figures.