Hello @rayt2,
I've never heard the argument about black coffee drinkers becoming psychopaths, but then again, it's not something I'd have made take up any space in my mind.
There'll always be arguments for and against some food consumption and the way we do so, that constantly changing.
I believe moderation and applying some common sense are key.
Yes, I've heard to coffee before a workout might not be good. Personally, I like to do my qi gong and yoga on an empty stomach, mainly because of the inverted positions. However, if I was lifting heavy weights was a part of my fitness schedule, then my common sense would automatically lead me to eat a meal preferably one high in protein, before engaging in lifting. That's simply because the body is like an engine to me, and I would never drive my car on empty oil.
Have a nice Sunday:)