On a fixie or a single speed? I'd be pretty impressed if you could safely mesh into a group of motivated road bikes.
I'm not sure I'd appreciate the wildly different braking dynamics between the different classes of bike though. Without conventional lever operated brakes on both wheels, your braking capability will always remain a hazard to the others.
You are free to replace your friends derailleur hangers, buddy flaps, fenders, etc... when you knock them down from behind. It would be an interesting experiment to see how how long they will remain a welcoming & friendly group of non-"elitist roadies."
Define the term: "Fast roadies."
__________________
I shouldn't have to "make myself more visible;" Drivers should just stop running people over.
Car dependency is a tax.