I'd try to keep it kinda narrow. Stuff that goes up and over your car isn't a problem as long as it's secure. Wide appendages are more likely to get knocked off.
Of course, there was the orange BMW with really wide fender flares at CMP once. They were made of corrugated plastic sheet, as I recall... and they completed the race mostly intact because they looked like in integral part of the car that you'd get dinged for "contact" if you hit. Big dangley crab claws probably wouldn't be viewed the same way, though.
Tech is mostly concerned with your "body parts" being secure and non-lethal. They don't want stuff falling off onto the track if they can avoid it, and they don't want the stuff that does happen to fall off to kill anyone!
Lemons South 2008 - Fail, Lemons South Spring 2009 - Fail, Lemons Detroit(ish) 2008 - Fail, Lemons South Fall 2009 - Fail, Lamest Day 2009 - Fail, Miami 2010 (Chump) - 2nd!, Sebring 2010 (Chump) - Fail, Cuba 2010 - Crew Chief, Roebling 2011 (Chump) - 8th!, Sebring 2011(Chump) - 19th!