(1) Weather: depends on the summer. Apart from a week of heat-wave and a few days around Memorial Day, this summer has been amazingly pleasant. I haven’t actually used my A/C in a few weeks, and I woke up at night two days ago freezing my b@lls off. Temperature had gone down to about 55, which was interesting with floor-to-ceiling windows open and a ceiling fan blowing.
Winter can be amazingly beautiful if/when it’s snowing.
(2) Apartments: small washer/dryers are becoming more and more common. Laundries in the basement are also pretty common. Sometimes at cost, sometimes free especially in smaller buildings. I don’t think that people smell worse than in other cities, though on a hot day where people actually walk, you may have a point.
(The rental condo in SD also has a common laundry, BTW, no unit in the apartment)
Not sure what your point is about replacing furniture and stinky apartments. It’s not really any harder to replace furniture in NYC than in other places. If anything, cheaper since you have less of it, though you may need to pay someone to lug it up the stairs of a walk-up.
(3) Much of the “sub-standard” housing is actually pretty well-constructed and less problematic than stuff built more recently. Depends on the landlord, the management co, and/or the general type of building I guess.