Re: nudity in cold weather.
I think in general, all nudists share one physical characteristic - great peripheral circulation. My wife constantly compains about sleeping with a living furnace - me. If you touch many friends hands and all of your friends hands feel cool to your touch - you may make a great nudist.
Alternatively, if all of your friends have warmer hands than you - seek tropical or semi-tropical locales.
Regarding the issue of clothing and socioeconomic status - I agree that socioeconomic status can easily be discerned in verbal communication, it's just that nudists don't seem to bring it up, even inadvertantly, like flying first class vs coach. (IMHO, telling others that one travels first class is akin to flaunting your wealth under any circumstance. Why do you think the airlines call it "first class"?)
Clothing and accessories frequently conveys socioeconomic status. Bare skin rarely does ( save for tattoos and plastic surgery and perhaps makeup)
Re. What are the functions of clothing. Always an interesting topic. Warmth, protection, symbolism, socioeconomic status, stealth (think ninjas), camouflage, enticement (think string bikini - what other purpose does it have), obfuscation (think robber in a ski mask), concealment, entertainment (think actors in costumes), deceit (think spy) and many others.
Re. - those embarassing male reactions. Again, amongst male nudists, this issue rarely arises. (Rim-shot)