Yeah I think if this logo had appeared in a Simpsons Episode or on Penny-Arcade it would clearly not be infringement. The fact that he's selling clothes changes things.
Exactly. Parodic or otherwise, he's using his riff on TNF's trademarks for commercial purposes. That seems to be the most important detail, in terms of how suits and rulings have trended, in my (admittedly brief) digging into the topic.