Note: this is from what I've picked up in ready dozens of reviews!

All songs are designed to just be played with the right hand, however in Pro Mode, songs on Hard and Expert difficulty require you to use both octaves. 

This means that there's no use for you to have a full sized keyboard, as it would leave most of it unused.

Pure speculation: 


If you can use a midi controller instead of the keyboard, you should be able to map certain keys to the five buttons. 
The velocity-sensitivity is probably intended to counter the fact that they're using very 'cheap' keys, which lack the natural resistance of a decent keyboard. My guess would be that you won't notice any difference in game. 
The lack of the expression bar is only a loss if you like using the whammy bar when playing it as a keytar, although you will lose the ability to gain extra Overdrive like you can with the whammy bar on a guitar. For the rest I don't really see a use case for it anyway.


What are the advantages/disadvantages of the Rock Band 3 Keyboard?
My son is convinced that it's best to go last in Vinci because you have the more complete information of seeing where other players have started their civilizations and you always get last turn (like having home field advantage in baseball). I see these 2 advantages, but I wonder if these outweigh the disadvantages such as not having first pick on civilizations, not being the first to go into decline, and perhaps other factors I haven't even considered (we're all new to the game). So:

Is it better to go first, last, in between, or is the game so well balanced that it hardly matters?
