Is it possible (as with the free Nokia maps app) to download the full map data on your PC and transfer to your mobile device to avoid always having to download map data as and when needed?
That is not possible. Both due to licencing and the way the program works. You'll find downloading the map data in real time is quick as well as only small amounts of data come down. Places on the map you've been to are cached on the device as well in order to reduce the amount of data used. We've done this to reduce the program footprint, plus the maps will be kept up to date on our side...