#1 in v2 the "illegal" is now a toggle - the text will turn red when it's on. It means that you can specify "high demand", AND illegal at the same time, in previous version this wasn't possibly. The setting in the detail window when you double click the row - DO NOT use the illegal entry in the drop down, ArchV1 knows about this "bug" and will correct it in there at some point (maybe an "illegal" check box will appear on that screen?).
#2 I've just tested this and you are correct, it does happen that way - I've not noticed this before as I have the main window (and trading window) on my 2nd monitor and the commodity window & details on my elite main monitor.
#3 range option? not sure what you mean with this, when you say two trade systems are you talking about something like LAVE & DISC systems, or two stations within the SAME system? for the former - this would be very complex as multiple systems connect to LAVE (depending on your jump range) and this application is not a "route finder" type of application. I think it's a case of if you trade in an area a lot, then you will automatically know the distance over time. E.G How far do you travel to work? How far is it to the supermarket - I bet you know these answers without excel telling you, but the first time you went, you had to work it out.
Now if your talking about stations from the main star distance (e.g. Lave star to the Lave Station) - 34ls, 250ls etc then you can use a custom field and just enter the number/text.