I tried searching for this but came up with nothing. So I am going to share the 2 exploits I've found.
First, you need to be on a Priest. Also you must be specced Shadow for this to work.
Make a 2 macros:
#showtooltip Shoot
/castsequence !Shoot, !Shoot
and now for the second one:
/cast !shoot
/cast devouring plague
Bind the first to 1, and the second to 2.
Now, press 1 then when your wand spell is in the air shooting at the target, spam your 2 button.
It will cast devouring plague repeatedly with no GCD. Repeat as needed.
****Also you can replace devouring plague with holy nova and there will be NO GCD!
Now for Invisibility make a macro:
/cancelaura dispersion
- Get on a mount of your choice and be in shadowform. Then, cast dispersion and then hit your macro. You are now invisible.
*Tested and working on Crusadegaming most likely works on many others
Enjoy!