Q: Why I cant see developer options?
A: developer options are hidden by google, go to about phone, tab build number 7 times and you will see a message "You are now a developer", go back to settings and they will be there.
Q: Where is advanced reboot menu gone?
A: Advanced reboot menu is disabled by cyanogenmod by default, go to developer options and check Advanced Reboot. Now press power button and you'll see what you were looking for.
Q: Where are pie controls?
A: Open build.prop and add this line:
Q: After enabling pie controls, how to remove soft keys?
A: Go to Settings => System => Extended Display => select status bar visible and then settings => power menu => Select Extended desktop and then finally power button => extended display
Q: Why is audio not transferred via bluetooth?
A: Flash Bluetooth fix patch