Welcome Gheudebert!
1. Analog not supported in F3
2. No, you don't need a pitlane or sensors. You can refuel/cahnge tyres etc anywhere on the track by pressing LC, or LC/BRK, depending on how you want It. It will open the pit menu.
Having said this, adding a pitlane, even without sensors, will add a lot to your track, otherwise you will be blocking the lane for other drivers.