Ok lets start this again calmly. First of all obviously it is not affected by Mirror coat and Snatch they only effect Special moves and Status moves respectively. Second I said in my answer that No Growl and Intimidate do not effect the Base power of the move but they do cut your Attack stat until you switch out. Then I stated the ways that Happiness is lowered. Third: The Question was:
If my Pokemon knows Return and the foe has the ability Intimidate and uses Growl, does that effect how much Return's damage is based on the happiness?
Fourth: Your original answer was:
Yes, return will be affected. Return is only not affected by magic coat and snatch
But it will NOT be affected in the sense that SEP was referring to in the Question so it was confusing and misleading because SEP said Based on Happiness, Growl and Intimidate do not effect happiness they effect the Attack stat. Which is why I hid it.