To 1: Can confirm that.
to 2: Well you didn't find an option to simulate that? It means its not simulated. That's why you can start the second engine without having to increase the thrust, although it's not possible in real life. At the moment not all or only a least "system" failures are really covered. Maybe Jar will do that in the future?
to 3. Well on an Airbus the logo light is always on if Nav Light switch is set to 1 or 2 and the gear is compressed or flaps are extended to more then 15°. So on ground it's always on (gear compressed) and therefore also during daytime, so it illuminates the tail the whole day. Of course sometimes you see it, where in real life you wont't see that, in X-Plane, but that's not a JarDesign problem, it's a x-plane problem.
To 4: It consumes fuel. Maybe a little bit to less, but to prove that maybe you have data from airbus how much fuel should be burned and make a comparison to the JAR bus?
To 5: On my computer the beacon does reflect on the engine fairing. Tried to catch it on a screenshot, but wasn't possible.
To 6: I would like to have an option with 180 passengers single class, next one would like to have an option with all buissnes class seats, next one will want to have an option with only one buissines class seat. So it's not perfect, but I can understand that Jar modeled only on option, due to the fact that otherwise they would have to model to much different variants. (Takes time, which should be used on other things). If you want to simulate some more passengers add more weights to the compartments..
To 7: Yes it shouldn't but i thinks it's an simplification, because otherwise you would have to write some more lines of code. (Maybe they fix that in the future?)
To 8: How do you descend? If am on managed descend I've never experienced that the aircraft doesn't reduce to 250kts.
To 9: Well can't confirm that they don't produce drag.
