Map editor is not available in the beta, but it is in the full game. Only one week until the release, please be patient 
I wonder, by the way - is it possible to have other buildings than those already present perform functions of those buildings? That is - we have, in the game (I'm talking about beta right now), I think, only one model for a hotel - the one that stands to the west of the Danube, just south of Rotenturmstrasse. Would it be possible for, for example, the building I've asked about above (or any other, for that matter), to be a hotel in a user-designed city? Or can currently a cinema look only like the orange one in the north of Vienna, and the shopping centre like the one south of the northern train station or the square one on the other side of the street from Stephansdom?
I have 3 questions:
1) Regarding bridges, can you build tram or ground-level/el rail bridges over water?
2) Can you connect to and "leech" the 'flavor' railways for your own ground-level/el rail metro lines?
3) Are there elevated rail stations?
A serious question about the map editor: Is it possible to make maps like the standard maps that progress by expanding over time?
i wonder why it was left out!!! Technical reasons or...? marketing reasons. From what i have seen in the building scripts, some of them have the year specified when it should appear ingame, like stadiums and airports for example.
you have too much faith in "that other map editor Microsoft Notepad"