Wi-Fi or Bluetooth Mobile Exploit

Most if not all phones are bluetooth enabled, we are advised to disable it when not in use. This is where my question comes in, is there a way to hack and control phones via bluetooth that have bluetooth "off"? and can one force pair? Whats the maximum distance to be kept between devices? Is it also possible to exploit using a phone?

What about exploiting phones that have Wi-Fi enabled? Is it a vector and what are the remote access tools that could be used?