Can I cast (Let's say Rejuv) on myself?
Yes:
/target Me
/cast Rejuvenation(Rank X)
But, would it be possible to make a macro where when targeting a friendly, I Rejuv them, but when targeting nothing at all, I target myself and Rejuv? I know I could go into interface and check the box "Auto self cast" but if I do that it screws up my addon.
Thanks