As for flat shading, one part of me thought that it would help reduce the geometry and therefore improve performance,
Well, with flat shading you do not need to split sharp edges (i.e. create duplicates of edges shared by multiple faces, which is what the Edge Split Modifier does in Blender) because all edges are interpreted as sharp. But the number of faces is the same and those additional edges won't have such an impact on performance if any at all.
First question: No, see the changelog. They'll definitely mention it there once this important functionality is available – you won't miss it.
Second question: Not exactly the same, but basically yes. You have to assign passenger area(s) to a bus station object so that waiting passengers know they can board a bus which stops at that station.
Impressive, thank you for telling us about your project! I love your enthusiasm. 
Rheindahlen
So you lived in my home city. Unfortunately I never visited the JHQ before it was closed in late 2013 and now it's derelict and no longer publicly accessible. Missed the chance to take some photos for a possible Lotus map including the bus routes going there.
And it was communicated from the start that there would be several modules and how much they would cost.
Hard to see what's happening on that tiny image. But my guess is you should check the orientation of the face normals.
Eingesetzt wird der Triebwagen aktuell nur noch als Schlepp-Fahrzeug.
Ah... Ich dachte bei der Aufschrift eher an eine Übernachtungsgelegenheit (passt ja auch zu den blickdichten Fenstern). 
There are different variants of this font because it has been reworked over time, which is quite obvious for the glyphs for 6, 9, t, a when you compare signs from the 50s with signs from later decades. The BVG rollsigns are from 70s, 80s, and 90s but that doesn't mean the manufacturer always used the latest font version available at that time. The only thing you can do is google. There's one free download of an old version of the Mittelschrift (i.e. regular typeface) made by Peter Wiegel available from his website that I found quickly: http://www.peter-wiegel.de/alteDin1451.html (download link is in top left corner).
They used more than one font: The classic DIN 1451 Mittelschrift and Engschrift (in different versions) as well as other fonts.
You have to specify a link for the aerial view in the editor settings in the required format. First task for you is to find a WMTS or WMS service that covers London. Then you can find out what's the link to enter in the settings.
You can learn a couple of things from Florian 's Twitch streams. 
You can set the list index in the properties window of the parking spot object. But I don't know if multi-selection works.
I can tell that boolean definitely works, too. I use that to show/hide a submesh of an object and that is also reflected in the simulation.
That texture on the sidewalk looks weird, like the larger stones consist of smaller ones, some of them including the gaps between the larger stones in their surface. Maybe you got the detail texture wrong?
It might be helpful for others to let them know how you fixed it.
Should i play Lotus in a little window, or what?
No:
1. You can enlarge the window after selecting the map you want to play.
2. This is obviously a known bug (I have the same problem) that will be fixed sometime in the future. But since it's not a showstopper, it's probably not high priority.
Seems to be fixed now? I was able to buy the module using the Steam client when logged in.
Could it be related to your track package (see Marcel's posting)?
"Nope" to which of the two cases above?
