Buy your kid an Ipad. Unlike Android, its OS is rather limited for tampering, no more than factory defaults, and this should be safer in case something bad happens to the software.
On the contrary Android is much more ¨flexible¨ for editing, but unless your kid is a software developer, that shouldn`t bother you.
Both devises are suitable for nearly everything and Android is somehow prone to viruses. As for the mouse, I don`t know, but they could be connected to keyboard. I doubt however, that you`ll need it with these rather big screens