Questions about Audi 80 Cabrio

Hello, I have now bought an Audi 80 Cabrio Bj. 1996 with 2.6 L automatic. I have a few questions for you 1. On my way home it was so about 550 km much to me with half tank filling on which the tank lamp turned. I immediately refilled to the next tank on the highway and 10 L. After that was again quiet for 50 km, after that again the same that the lamp turned on, what can that be? The display is still almost to half full. In the display there is something of 8.9 L average v. 2. Since On both sides of the seatbelts the seatbelts go very long again in reserve. 3. Both seats can no longer be folded? 4. When starting it smells strongly like fuel, (outside). Does Euro 2 5. In driving mode it makes strange noises from the drive, these go away again when gas is accepted and higher speed, I guess this comes from the tires, are Nankang mounted, but can also be something else? 6. The ignition lock is a bit difficult and you have to press this in the starting position with the key about 3 mm only then the key can turn? So that was it first. Greeting Pit