Im 6' 3.5" and only real mod is to remove the seat hump which I took to a local marine upholstery company to do. Then you can sit back further. I also tilted my handlebars fwd. I dont care about looks and no one would dare say anything to my face anyway.
wind isnt much of an issue at the speeds the PCX can do. if you want to keep more wind and rain off of you, you can alway fit the tall givi windscreen. however, in summer it is better to get as much wind as possible, IMO!
Side wind can be a issue, I am 6 ft 2 slim about 13.5 stones, when I am riding in strong winds the bike can get blown about a bit, You do get used too it but you might have to stick clean pants on when you get home
Me, my wife, my dog, and camping gear all summed up is about 350lbs. We've been on several 100+ mile trips and been fine. The suspension is lacking with that much weight, but you'll certainly be more than fine.
My brother-in-law is 6'5" and is perfectly comfortable on the PCX. I'm not sure if he rode long enough to mind the hump, but worse-case scenario you can remove it.
you your wife and your dog... sounds dangerous I know pcx can carry around 400lbs my only fear was doesn't look good on pcx but thanks to taz and other guys.. they destroyed it
i'm 6'2 and have ridden the pcx fine for the last 2 years, on long rides in the cold you sometimes wish that hump wasn't there so you can stretch your legs a bit, but otherwise, not a problem. your knees won;t hit the handle bars like on some scooters
I am 6.3 feet and around 200 pounds. 
