On Question #7: If you go to the official Rise of Flight Website http://riseofflight.com/,there is a Free to Play version to Download. Basicly it's the full game with 2 Flyable Planes but minus the additional content like other Planes or Maps. You can upgrade the Free to Play version by buying single Aircraft or other content in their Shop if you want to. Just something you have to take into account,you can NOT mix and match the contents of the Steam version with the stuff you may buy in their Shop. As far as I know the Steam contents are bundled,thats why it seems so expensive. In the Rise of flight shop you can buy single Aircraft or get a discount when you buy 3 or more. There are sales several times a Year giving a nice discount also. 
It's certainly up to preference,but in my opinion the  Non-Steam version is much more convenient and practical, especially if you want to upgrade only 1 or 2 Aircraft at a time. It's a very well made simulator and if you enjoy those early planes you should give it a go. 
  
Edit: It may seem expensive paying between 6$ and 10$ for a single plane, but there is a lot of efforts put into the flightmodells and the 3d models of those aircraft. Once you took a few flights you will now what I mean...those virtual machines are just beautiful and well made.