A:Answer7 or 8 is probably the perfect age range. It will take adult help to initially assemble it, but after being shown how to use it, they should be fine.
A:AnswerThe instructions are interactive and best used on the Switch as you get an interactive 3D view of the build as you follow it in real time. That said there are Youtube videos of others building theirs while following the instruction on the Switch game. https://www.youtube.com/watch?v=hZ1Ygg0TZ8E Still I don't know how much I would recommend not using the Switch to build it. Maybe they could help each other find the necessary sheets and parts or one moves rotates the instructions as the other builds, just an idea. Good luck.
A:AnswerYou will need an extra pair of Joy-Con, which are sold seperately. The Switch Lite cannot charge Joy-Con either, so I highly reccommend also purchasing a Charging Grip.