Some questions on the Ambernic RG35XX pro(what does the double X mean anyways?)

So from my area this one looks like the only one available. I've done a bit of research and am aware that Ambernic is something like Analogue but with emulation and do not support physical carts.

The thing I want to know is with this Pro would I be able to play Dos games and specific Retro PC games like Rayman, Claw etc?

And how fixable is it interms of Screen and battery? Would any technician be able to fix it?