Make sure you return it with the same amount of fuel they gave you on day 1, i.e. 2 gallons
As for the tyres, that's an interesting one. Is it not mentioned in the small print? As long as they are legal and have no damage (punctures, sidewall bulges etc) I can't see why they would bill you for a fresh set tbh......but then again, s/hand car buyers use worn tyres as a bargaining chip.
Are you taking out another lease from the same place? If so, they'd probably turn a blind eye to the small stuff.