Is buying a chinese phone risky???

Depends what are you worried about?

If it is about build quality it just depends on the price and if you buy it from a website with a reputation like Gearbest you will most likely not be delivered a bomb.

But if your concern is privacy then it's a shoot in the dark, my recommendation would be get a phone with a reputation for being a good phone for rooting and custom ROMs and install a custom ROM