Safe as you are afraid google will bann your accaunt for using it in emulator or safe as you are afraid of viruses?
In first case,dont worry, i know lots of people using buestack for years to play android games on PC, even youtubers do it publicly to stream games.
As for second case, that depends on your PC security ,as long your PC is safe,bluestack will not endanger you either.And also, you can install aditional android security compoments inside bluestack it self, just like you install it on regular android phone.
You can also research net abaut bluestack, this page for example can give you near all basic data you need to know:
BlueStacks is one of the most popular Android emulators out there, but is it safe? Does it slow down your computer? We have answers.
www.androidauthority.com