I think the most common faux pax to happen on the bike path is when some guy with more money than skill decides to buy fancy wheels, that he then decides to train on.
Here's the deal: Carbon wheels are light, fragile, and awesome. The purpose of them is to make you a very small percent more aerodynamic, and thus faster at speed. The only time you need to be 1% faster is in a race, so you DO NOT NEED THEM while riding on the path, or going up lookout about as fast as one of those paragliders comes down. Riding ridiculously expensive wheels when you aren't racing is really just a big red flag that tells us all that you aren't fast, and like to waste your money trying to impress us.
Don't tell me about how "it's your money" or you'll "ride what you like." A better use of your money would have been a powertap and decent training wheels, or better yet, a cycling vacation so you'd actually BE fast, and not just be a tool who thinks they look fast. The ONLY reason to ride deep carbon wheels on the bike path is so that others will see you on them. You want to impress us, not give us fodder for ridicule, so leave the zipps and reynolds at home, until you're actually ready to race.