The dudes brain is broken. The thug beating his @$$ must have damaged him... assuming it wasn't broken to begin with.
Throwing stuff in the gears of the P.C. machine and you are calling him a kook... well maybe he’s saner than those who shy away! Check a mirror.
He sells what people want. There are already tons of paintings you describe. When customers get enough, then he will go to what they are looking for or go out of business.
The flag has come to mean "rebel" over the last half century, as much as its historical meaning, and is only recently being sold to the people as "racist" by those who are making a good living selling soap between segments of biased "news". That same media are the ones who tried to foment riots, led to Zimmerman having a price on his head (NBP: $10K dead or alive), and this, along with allegations of "racism" by a gun shop owner who refuses to sell to Muslims, is thumbing their noses at the media.
I would rather look upon a Confederate Battle flag than a lot of the things that pass for "art" out there. Besides, some of my ancestors and relatives fought under that standard.
As for sports "heroes", you would compare them with people who placed their lives on the line to defend their homes and families? The one out there right now all over the media isn't even known for sports so much as being "transgendered".
That to me is plenty to rebel against.